eu4 how to become emperor

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Traditions:

+2 Diplomatic reputation

+1 Possible policies

The Imperial Throne

+1.5 Yearly legitimacy

Kaiserliche Armee

+15% Morale of armies

Imperial Diplomacy

+33% Improve relations

Centralized Empire

+20% National tax modifier

Roman Heritage

−20% Core-creation cost

Adopting the Goosestep

+5% Discipline

Onwards and Upwards

+10% Governing capacity modifier

Ambition:

+5% Administrative efficiency

The HRE in 1444. The emperor is in purple. Electors are orange. Free cities are blue. Dark green are Imperial provinces, owned by HRE member-states or otherwise.

The Holy Roman Empire (HRE) is a unique political structure in the game, made up of numerous variously-sized states of the Germanic region and northern Italian Peninsula in Europe. Members are considered 'Princely states' and their heads are 'Princes'. From these Princes, up to seven are Prince-Electors, who vote on which Prince will be the next Holy Roman Emperor upon the death of the previous one. The Holy Roman Emperor has various powers at his disposal and a great deal of responsibility to maintaining and protecting the Imperial territorial, religious, and cultural status quo. In the Common Sense DLC, the Emperor can appoint up to twelve Free Imperial Cities which are OPMs, cannot be electors, and give the emperor more authority in exchange for trading bonuses (for example, Ulm).

Historically, the Empire existed from the 10th to the 19th centuries, and had up to 300 members at some points, many of which were so small (e.g. the grounds of an imperial abbey) that they are not represented in EU4. The first Holy Roman Emperor, Charlemagne, was crowned "Emperor of the Romans" in Rome by the Pope in the year 800, but it wasn't until 962 that the HRE as a united polity came into being. It considered itself to be the spiritual successor state to the Roman Empire, even though throughout the majority of its existence it never directly controlled Papal Rome (and also despite, up to 1453, the continued existence of the Eastern Roman Empire and until the late 15th century of various Byzantine holdout states such as Trebizond, Theodoro, etc.). It experienced high amounts of decentralization towards the end of the Middle Ages, which is represented in-game by the special HRE mechanics (see below). The balance of power between the various Princes, Electors and the Emperor was always in flux, and imperial unity was further weakened by the Reformation. From the 15th century on, except for a handful of years under the house of Wittelsbach (during the early years of the reign of Archduchess Maria Theresa) the Emperor was from the House of Habsburg or Habsburg-Lorraine, the rulers of Austria and many other European nations.

Game interface

The Holy Roman Empire interface, showing Austria as the Emperor, six electors (5 voting for Austria), eleven Free Cities, and 37 other princes. Religious leagues are forming: on the left, the Catholic League led by the Emperor (Austria); and on the right, the Protestant League, here led by Brandenburg. The green tick indicates that the player is a member of the Catholic League.

The Holy Roman Empire interface is a small shield (with a picture of an imperial eagle) on the bottom of the screen (only visible as long as the HRE exists). Under the icon is a number which shows the authority of the current reigning Emperor.

Within the interface are a number of shields of various sizes representing members of the HRE. Each of them can be clicked on, which will bring up the diplomatic interface to examine and interact with that nation.

Religious state: In the top right of the interface is an icon indicating the current state of religious law within the Empire. At the start of the game, this is a gold cross indicating that the Catholic faith is official. When the religious league forms, it changes to an icon indicating a "state of Religious War"; when this state ends, it changes again, possibly back to Catholic, to Protestant, to Reformed, or to an icon reflecting that "a treaty of permanent religious peace has been established".
Current Emperor: The large shield in the upper left corner shows the blazon of the country who is currently the Emperor. Beneath the shield, the game will state specifically the name of the current Emperor, e.g. "X is the Emperor".
Imperial Actions: Hovering over the dove icon to the left of the Emperor's shield shows what special actions are available to the Emperor.
Benefits: Hovering over the icon of the imperial crown to the right of the Emperor's shield shows the current benefits granted to the Emperor and to princes.
Imperial Authority: The white number in at the top of the interface shows the current imperial authority to two decimal places. Hovering over it shows a list of factors that can affect it. The red or green number below it shows how much imperial authority changes each month, and its tooltip shows the factors that currently affect it.
Reforms: In the center is a list of possible imperial reforms; hovering over them reveals their tooltips, which show the reforms' respective benefits for princes and the emperor. They must be passed in order from left to right. Once passed, the reform's icon gains color. The reform's icon has a tooltip showing which princes are in favour of or against the next reform, and can be clicked by the Emperor to pass them. Members other than the emperor have a small box in the bottom right corner each reform that can be ticked to vote in favour, or unticked to vote against.
Electors: These are the seven princes that have the power to elect the next Emperor. Underneath each of their shields is a smaller shield, representing that elector's current choice of successor to the Imperial crown. They can vote for themselves if eligible, or for other nations. Dependent electors will almost always vote for their suzerain overlord if eligible, even if they are not part of the Empire. Next to it is a number which represents that elector's current support of the player's own ruler as successor. This will range from a positive number, which means the Elector favors the player's ruler over all others, to a negative number indicating someone else is favoured, to less than −1000 if the player's ruler is ineligible to be Emperor. Hovering over the shield will display a tooltip showing all the factors that play into the elector's current attitude towards the player and the elector's (next) favourite.
Princes: Below the Imperial Diet is a display of all the shields of the current member states of the Empire. This number can shrink or grow over time as member states are conquered or new ones find a home within the Empire's boundaries. Electors are listed first, distinguished by a seal icon with an E attached to the top left of their icon. Imperial Free Cities are listed to the left of the princes, distinguished by a white banner crossing behind their shields. Hovering over any of them shows their current attitude towards the next reform and a breakdown of factors contributing to it.
Leave HRE: At the bottom left is a button for those who have had enough of the Emperor's meddling in their lives. Selecting to Leave HRE will take the member's nation out of the Empire and remove all of its provinces from the Empire. However, there are diplomatic consequences to such a decision.
Dismantle HRE: If the Emperor's capital is controlled and the electors either have their capitals occupied or are allied to the nation attempting to dismantle the empire (almost always the player), it is possible to dismantle the Holy Roman Empire and disable the HRE mechanics permanently, which also grants 100 bonus prestige.
Religious leagues: If any elector converts to either the Protestant or the Reformed religion, a Protestant country will form the Protestant League in preparation for religious war against the Emperor, who forms his own Catholic League. The members of these leagues are shown on panels to the left and right (Catholic and Protestant respectively). Above these panels is a button which a non-member can press to join the league (not available to the Emperor, who always leads the Catholic League).
Imperial Diet: Under the imperial reforms is the Imperial Diet. Here, past and current imperial incidents and their outcomes are displayed. During an incident, the current incidents section displays multiple buttons for the incident's outcome. Clicking on a button supports that outcome, and hovering over them displays which princes support which outcomes. The Emperor can also select an outcome for the incident, ending the incident with that outcome.

Emperor

The Emperor is the leader of the Holy Roman Empire, tasked with defending and maintaining the sovereignty of member states.

Friedrich III von Habsburg of Austria starts the game, in 1444, as Emperor.

Electing the Emperor

See also: #Electors

Emperors, once chosen, serve for life. However, if the emperor becomes ineligible, or is annexed so his/her nation ceases to exist, a new emperor will be elected. On the death or disqualification of the current Emperor, the Imperial Electors choose a replacement from within the Christian world, with the exact eligible denominations determined by the outcome of Religious Leagues.

An Emperor can only be selected from candidates that are:

Male (unless the Pragmatic Sanction decision has been enacted by an Emperor with a female heir)
The accepted Imperial religion (either Catholic or Protestant). If the Peace of Westphalia event happens, any Christian may be chosen (although a −50 "Heretic Nation" penalty goes toward the nation's score on the electors' opinion, not to mention the relations hit), including Orthodox and Coptic nations.
Independent rulers (i.e. not a subject)
Monarchs (i.e. not rulers of republics or theocracies)
Leading a country with the capital in the same continent as the current Emperor's capital
Has NOT enacted the "Revolutionary Empire" goverment tier 1 reform

If there is no candidate qualifying these conditions, most often from the outcome of religious league war and all of the rulers of that religion being female, then the Empire is automatically dismantled and the HRE ceases to exist.

Notably, being a member of the Empire is not a requirement, though electors will usually prefer members.

Election happens immediately once a new Emperor has to be chosen and the candidate with the most votes wins the election. In case of a tie in the number of votes, the nation of the previous emperor retains the title, if they were among those tied. Otherwise, the tied candidate whose country has the highest prestige wins the election.

An Emperor cannot lose the election for Emperorship while in the midst of a League War.

Benefits of being Emperor

The Emperor gets the following bonuses:^[1]

	+10%	Spy network construction
	+1 %	Possible advisors
	+1 %	Diplomatic relations
	+1 %	Leader(s) without upkeep
	+1 %	Yearly prestige

Additional, for each member state of the HRE:^[2]

Additional, for each Free City in the HRE:^[3]

Additionally, the Emperor may core any province within the Empire, even if it's out of coring range or inaccessible.

If a non-member is elected emperor, their capital and all european provinces which have a land connection to the capital are added to the HRE, making him an HRE member.

Powers of the Emperor

The Emperor has the following powers and duties:

Bestow Imperial Grace

This action gives the Emperor a +50 relationship modifier with another nation within the Empire at the expense of −1 Imperial Authority. This relationship bonus will disappear if the country stops being emperor.

Propose Imperial Reforms

Available from the Holy Roman Empire interface, the Emperor can call for a vote on an Imperial Reform. Unlike in EU3, the Emperor can see how the members of the Imperial Diet will vote before calling for the reform by hovering over the reform button, and why they support or oppose by hovering over the shields of each imperial prince. A prince's decision to support a reform is largely based on their opinion of the emperor, the amount of imperial authority and the emperor's diplomatic reputation.

Grant Free City Status

Grant Free City status to nations in the HRE that only own one province. Free Cities get a special republican government, a bonus to tax income and will always be able to call in the Emperor when they are attacked, even in internal HRE wars. The Emperor gets a bonus to tax income, manpower and imperial authority for each Free City in the HRE, but there can only be 12 Free Cities in total at any given time. A Free City that gains a second province or leaves the HRE will lose their Free City status. Free Cities cannot be Electors. Monarchies get a −50 penalty to accepting and theocracies get −100 , so getting one-province republics released may be necessary to create more free cities. A nation that feels Threatened by the Emperor will have a +20 modifier to becoming a Free City, so that they can have guaranteed Imperial protection. Friendly status or being allied gives +10 , relations give up to +20 and each point of diplomatic reputation give +3 .

Defend the Empire

The Emperor receives a call to arms when outside powers declare war on a prince of the empire, or members declare war on each other without a casus belli. Unlike a regular Call to Arms this does not usually have an effect on prestige, but does affect Imperial Authority. If the emperor decides to refuse this call, Imperial Authority drops by −10 . Regardless of the outcome, answering this call to arms gives the emperor a +50 relations boost with regular members of the Empire, and +100 with the electors. The opinion of the nation that was under attack will increase by +10 because of the honored alliance relation boost.

Revoke Electorate

Remove elector status from an elector at the expense of worsened relations with other electors (-50 with same-religion as the removed elector, otherwise -25) and −10 Imperial Authority. This action is not available unless the HRE has an official religion and the elector is considered heretic.

Appoint an Elector

If there are fewer than seven electors in the Empire, the Emperor can appoint a new Elector in the diplomacy screen to any independent nation inside the Empire. Appointing an elector gives a +50 relations boost with the new elector. The emperor cannot make Free Cities, Subject Nations, or himself electors.

Imperial Ban

Once the first imperial reform has been passed, The Emperor gains a casus belli against all non-HRE nations that control any HRE territory, such as Burgundy or Venice at the start of the game. HRE territory owned by non-members is shown with yellow diagonal lines in the Imperial map view. If an outside power conquers the target province, the emperor gains a claim on the province.

Imperial Liberation

The Emperor gains a casus belli against nations that annexed a member state, with the goal to liberate the said prince. Succeeding to liberate the prince will result in an imperial authority bonus. The casus belli is automatically given upon the annexation, and expires in 60 months (5 years).

Enforce religious unity

This is a diplomatic action which allows the Emperor to force his/her state religion on other nations within the empire that follow heretical denominations. The acceptance of the request depends on the target nation's opinion of and attitude towards the Emperor, the Emperor's diplomatic reputation and prestige, the target nation's number of provinces and whether the target is an Elector. If the target is an elector, free city or Defender of the Faith, it counts for a −1000 points reduction on the likelihood of acceptance, effectively rendering peaceful conversion impossible. If the target accepts the request, they convert to the Emperor's state religion and one random province becomes converted automatically. The Emperor suffers a relations hit ( −10 which is cumulative up to −100 ) with other Princes with the heretic religions of all denominations. If the target refuses to convert peacefully, the Emperor suffers a prestige hit and gains a casus belli against the target. It can only be demanded after a religion is set in the HRE, meaning that if the Peace of Westphalia is signed, this option will be permanently locked, but will be available after 1635 if the League Wars are never triggered for example (see Religious Leagues). Demanding religious unity, whatever the answer, costs 1 point of Imperial Authority.

Demand unlawful territory

The Emperor can demand another nation, member or not, to return unlawfully held imperial territory to the Emperor, refusal of which gives the Emperor an Imperial Liberation casus belli and gives all member states a relations penalty with the unlawful land's holder. The territory is considered unlawful if the owner does not have a core on it. Denying the request will also result in higher unrest, lower tax and manpower and a negative monthly autonomy change in the recently conquered province. If target country refuse the Demand, Holy Roman Empire loses −1 Imperial Authority. Demanding causes a −100 relation penalty with the target, so it is probably worth it to let an Elector keep its spoil of war instead. If the same province is taken twice by different or same nations the emperor takes ownership of that said province.

Re-election bonus

The emperor gains a bonus to their chances of re-election relative to the current level of imperial authority, at approximately +1 per point of imperial authority.

Imperial authority is used to pass reforms within the Empire and perform certain Emperor actions. The Emperor needs at least 50 Authority to pass a reform and the consensus of at least half of the members of the Empire. When a reform is passed, all Imperial Authority is removed (the counter is set to 0). After the reform Proclaim Erbkaisertum has been passed, the emperor gains an additional +25% Imperial Authority to every action taken. Imperial authority is capped at 100 .

Imperial Authority changes as follows:

Imperial Authority modifiers

Winning a defensive call to arms will grant as much as +30 IA, in addition to a substantial relations boost with every HRE member nation. Only awarded when the defensive War Leader negotiates a victory, so not on separate peace deals.
+10 for maintaining the Imperial Crown through successive generations until the Erbkaisertum reform is passed. Note that this does include re-elections triggered by the Emperor's abdication, "manually" or due to pretenders enforcing their demands.
+5 when a nation joins the Empire.
+0.10 monthly if there are no internal wars in the Empire.
+0.10 monthly with the Brandenburg idea 'Seat of the Old Emperors', Goslar idea 'Kaiserpfalz' and Mantua idea 'Free Imperial City of Mantua'.
+0.005 monthly for every Free City in the Empire.
+0.003 ^[4] monthly for every Prince over 25 in the Empire.
-0.003 ^[4] monthly for every Prince below 25 in the Empire.
−0.005 monthly for every province owned by a country not in the Empire. This also applies for provinces owned by HRE members that are (non-tributary) subjects of non-members (for example, Provence leading a PU with Lorraine, Holstein in vassalage to Denmark). Provinces owned by non-HRE members who are subjects of HRE members do not decrease IA, although they are still subject to the Imperial Ban.
−0.1 monthly for every elector who is a vassal. This does not apply to electors who are junior partners in a Personal Union.
−0.1 monthly for every electors below seven (below eigth if reform Embrace Rechenschaft Measures was taken).
−10 for declining a defensive call to arms from a member being attacked by a foreign nation.
−0.01 monthly for every heretic or heathen prince in the Empire. (This includes Orthodox and Coptic religions, and is halved once Religious Peace has been proclaimed.)
−1 to Enforce Religious Unity on a Heretical member of the HRE.
−1 when Demand Unlawful Territory is refused.
−5 to Revoke Free City Status.
−10 if a non-HRE nation annexes a member of the HRE.
−10 if a member leaves the empire

Imperial authority growth modifier

The imperial authority growth modifier increases the gained imperial authority:

	Conditions
+25%	after the imperial reform 'Curtail the Imperial Estates'.
+25%	after the imperial reform 'Proclaim Erbkaisertum'.
+25%	after the imperial reform 'Revoke The Privilegia'.
+25%	with triggered modifier 'Catholic Empire'.
+25%	with triggered modifier 'Protestant Empire'.
+25%	with triggered modifier 'Reformed Empire'.
+20%	as catholic while the Golden bull "Libertas Ecclesiae" is active.

	Traditions	Ideas	Bonuses	Policies
+10%	Bohemian traditions	Austrian idea 1: Imperial Ambition	—	—

Empresses

If the Emperor has a female heir he can, under certain conditions (legitimacy >= 90, prestige >=1 and imperial authority >= 25), take the decision that in the future women can become empress. This is not needed if Proclaim Erbkaisertum has been passed. Historically, Emperor Charles VI, who had no male heirs, issued it in 1713 to provide for the succession of his daughter Maria Theresa, which nonetheless led to a succession war in 1740 (the War of the Austrian Succession).

Pragmatic Sanction

Our heir is a woman but the Imperial crown can only pass to a man. It would be intolerable if our dynasty should lose their hold on the crown they worked so hard to acquire due to a mere technicality. Let us use all our influence to ensure our female heir will be considered as our successor when the time comes to elect a new Emperor of the Holy Roman Empire.

Potential requirements

The country:

is a member of the Holy Roman Empire.
has not enacted this decision before.

No female can become emperor.

Allow

The country:

is the emperor of the HRE.
has a female heir.
has a legitimacy of at least 90.
has at least 1 prestige
has an imperial authority of at least 25.

No female can become emperor.

Effects

The country:

The Pragmatic Sanction

The Pragmatic Sanction, solemnly rendered by Emperor $EMPERORNAME$ on [GetDateText], established the indivisability of his lands and established succession by order of first born child, even to a woman. No doubt $EMPERORNAME$ also plans for his female heir to in time take his seat on the Imperial Throne.

Trigger conditions None	Is triggered only by By the decision 'Pragmatic Sanction'.
We can have an Empress! Females can become emperor.

Further decisions

Rein in Italy

The Italian Princes must be reined in either through diplomacy or war. We cannot allow Italy to become a shadow kingdom!

Potential requirements Is Emperor Doesn't have global flag italians_leave_hre Is before year 1500	Allow The Emperor has formally decided to rein in Italy All Italian Princes have been reined in.

Effects set_country_flag = shadow_kingdom_early_success Every country that has not been reined in may leave the Empire! (gets The Shadow Kingdom event)

End the Great Peasants' War

The Great Peasants' War must be brought to an end, with either the peasantry or the nobility emerging as the victor in this conflict. As the peasants enforce their demands or create new republics, they come closer to enforcing their demands. But when a new republic is crushed, the tide turns in favour of the nobility.

Potential requirements The Great Peasants' War has started in the HRE is Emperor	Allow Doesn't have any active Imperial incidents Peasants' War Progress must be greater than 9 or less than -9 .

Effects Imperial incident "The Great Peasants' War begins

Enforce Peasant Demands

For too long we have suffered under the tyrant heel of the nobility. Peasants' War Progress is gained when countries become Peasant Republics or when they collapse to Peasant rebels.

Potential requirements The Great Peasants' War has started in the HRE Has government reform Peasant Republic Is member of HRE	Allow Doesn't have any active Imperial incidents Peasants' War Progress must be at least 10 .

Effects Imperial incident "The Great Peasants' War begins

Electors

The Electors are the nations that vote for the next Emperor. When there are fewer than seven electors, the Emperor may grant the electorate to another independent nation within the Empire. Electors are incredibly protective of their sovereignty and are unlikely to vote for a nation that has an elector as its vassal. The Emperor may go to war with a country in order to remove the electorate from them if they follow a heretical denomination; with Common Sense, he can simply revoke the electorate instead (and can't go to war to do it). Electors may vote for non-members of the HRE too. There are two ways to become an elector. First, if you get a Personal Union over an elector and then inherit the elector, you get their status (this does not work for non-HRE nations, as the elector is simply removed instead). The second is to be assigned by the emperor. AI emperors will assign nations they have good relations with, and that are the dominant religion in the empire. They will not assign a nation of a different religion to be an elector. The emperor prefers small princes, as they fear large ones will only vote for themselves and take the Emperorship. They still have this fear even if the large nation is a republic or theocracy, thus making it impossible for them to become emperor. Each province over three the prince owns reduces the likelihood they will be an elector. Thus, if the player wants to become an elector they must either inherit one, or be the dominant religion, same religion as the emperor, have good relations with the emperor, and be small. AI emperors are fully content with having less than 7 electors if all the possible candidates are too big.

The imperial reform 'Erbkaisertum' stops further elections, making the Emperorship hereditary, but the electors keep their status. Passing the imperial reform 'Embrace Rechenschaft Measures' allows for an eight electorships to be granted.

If there are no electors in the empire, hereditary rule is instituted.

These states begin as electors in 1444:

Bohemia
Brandenburg
Cologne
Mainz
The Palatinate
Saxony
Trier

AI voting criteria

AI electors weight candidates according to the following criteria (non-exhaustive list), although an AI elector with the backing of another elector will vote for itself regardless, as will an elector with a "strategic interest [in] becoming emperor" (although the conditions for this are not explicitly stated).

+ current opinion, from −200 to +200 .
+1 for each point of legitimacy over 50 and −1 for each point of legitimacy below 50
+ Prestige / 4, from −25 to +25
+ Imperial Authority, for the current emperor.
+30 for an alliance with the candidate.
+10 for a royal marriage with the candidate.
−25 , if a one-province minor.
−25 , if under 50 development ("Too small nation").
+25 , if above 100, but below 200 development and an HRE member ("Large Nation in the Empire").
+50 , if above 200 development and an HRE member ("Large Nation in the Empire").
+5 for same culture group.
−50 for heretic religion (i.e., different branch of Christianity).
+50 for subject electors, towards their overlord.
−50 for independent electors towards a candidate with electoral subjects (stacks).
−50 for non-HRE states.
+200 for being the leader of a religious league. (The leader of the Protestant League will be Protestant and thus ineligible.)
−200 for being a member of the opposing religious league.
+10 per point of positive diplomatic reputation.
−5 per point of negative diplomatic reputation.
−200 if at war with the candidate. (NB: this is a severe penalty, but not automatically disqualifying).
−1000 if ineligible (non-monarchy, having the States General reform, female candidate before Pragmatic Sanction, not HRE religion or not independent, in a regency or interregnum, or the Emperor with no eligible heir).

Princes

Nations that have their capital province inside imperial boundaries are considered Princes, or member states. These are the non-electoral states that begin the campaign in 1444 as part of the Empire (Though Italian princes (marked in Bold) will leave should the Emperor choose to let go of Italy during the "Shadow Kingdom" Imperial Incident.):

Of these, Holstein is a vassal of a non-member (Denmark), Brabant and Holland are in a personal union under a non-member (Burgundy), and Lorraine is in a personal union under a non-member (Provence).

Adding provinces to the HRE

Open the HRE interface and bottom left the "Join HRE" button will not be greyed out and selectable if the provinces you want to add to the HRE are cored, in Europe, "can connect to the Empire" by bordering an HRE province via land connection or shared sea tile, and the nation is 1) the Emperor, or 2) a member of the HRE and the Emperor has an opinion of it of at least 100, or 3) a non-member of the HRE and the Emperor has an opinion of it of at least:

For example, in 1444 Venice has 147 development. It also has Naxos and Corfu as vassals and their development is 6 and 9 respectively. So it requires (100 + 73 + 3 + 4 = ) 180 opinion from the Emperor to join. Since relations can't exceed 200, this means that a nation can't have more than 200 development. Since vassal's development counts equally, releasing provinces to vassals can not help in adding provinces or joining the HRE.

Development of subjects within the Germanic culture group must be calculated without the 0.5 multiplier. For example, in 1444 Burgundy has 144 development. Its Francien vassal Nevers has 27 development; its Germanic personal unions Brabant, Holland and Flanders have 53, 45 and 34 development respectively. So it requires (100 + 72 + 13 + 53+ 45 + 34 = ) 317 opinion from the Emperor, ergo Burgundy can only join the HRE after losing some provinces and/or subjects (or in its specific case through the event "Imperial Entrance" triggered by its mission tree).

Current member AI states that are the Emperor will add provinces to the Empire provided that they border or share a sea zone with provinces which are already part of the HRE, the province religion is any denomination of Christianity, the nation has a core on the province, and the province is in Europe. Provinces connected with a water crossing can be added to the empire, as well as isolated islands provided they share a sea zone with a province already in the empire.

Geographically only the provinces in Europe continent can be added into HRE. Be aware that regions do not correlate to continents 100% - e.g. most of Anatolia region belongs to Europe but Kurdistan area belongs to Asia. Similarly with Caucasus and Armenia. That means that Armenia and Kurdistan cannot be added into HRE.

Removing provinces from the HRE

Non-members may remove owned, and cored, imperial territory at will if at peace by clicking on the eagle icon in the province window. This lowers imperial authority by −1 and significantly hurts relations with the emperor.

Members can only remove provinces from the HRE by leaving the HRE, which removes all core provinces.

Joining the HRE

Since a nation is a member of the HRE if and only if its capital province is in the HRE, it is possible to join the empire by adding the capital province to the HRE according to the rules described above, which for non-members require the country to have sufficiently low total development (200 or less; regardless of culture) and good relations with the Emperor. Joining the HRE will add all owned provinces to it, though they will not add any imperial authority. Joining will also cause the Emperor to gain 5 imperial authority. If a non-member is elected emperor, they can choose to join - using 'Join HRE' button in the HRE menu - the HRE and all their european provinces which have a land connection to the capital are added to the HRE.

Alternatively, while you can't move your capital into or out of an HRE province normally, such a move can still happen by other means like events or losing your current capital (at least if there is no other province of the same HRE status as the lost capital), and will result in respectively joining or leaving the HRE. Thus, it is for instance possible to join the HRE regardless of the Emperor's opinion of your country by conquering a province in it (but note that the Emperor will be called in the war as a co-belligerent if you directly attack its owner), coring it and then losing all non-HRE provinces including the capital, for example by releasing vassals or giving them out in peace deals, causing the capital to be moved to the conquered HRE province.

Minor AI countries may rarely join the HRE if they have excellent relations with the current Emperor and they are threatened by a powerful neighbor (Ragusa in fear of the Ottomans, Gotland in fear of Lithuania/Sweden etc.). Using the console command "mapmode aihre" you can see some of how the ai evaluates this decision. It seems to compare the threat level and relative strength of one particular nation that it feels threatened by, which need to be greater than 300-(2*(HRE Imperial Authority)) for threat level (maximum 400) and less than (HRE Imperial Authority)/2 for relative strength (as a percentage). It also does not want to join if the nation it evaluates for this is already a member of the HRE, even if some other non-hre nation might have the appropriate threat/strength levels, it seems to choose whichever nation it finds most threatening, and it seems to give preference to rivals and nations with cores or claims, for instance, Dauphine might evaluate for its rival Savoy instead of France, if France has no claim/core on its territory, even if it feels threatened by France. Additionally it will still consider nations which it has alliances or truces with and re-evaluates this on a monthly basis, though it seems to give these a lower priority, other things being equal. The nation's attitude toward the emperor also seems to affect the decision, and nations that are not able to reach the needed relations level don't seem interested in joining either. An example is the Teutonic Order in 1444 which needs 149 relations with Austria to join, if Austria guarantees them and asks for military access they can still only reach 145 relations and will not be interested in joining, but once the event fires for them to sell their hre province back to Brandenburg, the relations requirement will drop down to 144, which is achievable and they will start working towards joining. Once it does decide to join it will do so as soon as it meets the relations requirements and can add its capital.

Leaving the HRE

A member state who is not the Emperor may leave at any time if it is at peace (using the HRE interface). It is also possible to leave by moving the capital to a non-HRE province; however, this cannot be done manually, but can happen by losing the capital or some events.

Leaving causes non-core provinces in the HRE to be ceded to the emperor, removes all core provinces from the HRE, hurts relations with the emperor and reduces Imperial Authority by 10 .

Non-electors forming nations results in those nations leaving the HRE, unless they are the emperor or an elector (e.g. if Holland is the emperor, Holland can form the Netherlands without leaving the HRE). Also should the North Italian region not be entirely in the HRE by 1490 the Italian states will leave through the "Shadow Kingdom" event. An Italian country is considered under control for Shadow Kingdom incident if it has lost any war against the emperor, or it is allied to the emperor, or it has an opinion of 150 toward the emperor, or it is a subject of the emperor, or it is a free city.

Free Imperial Cities

Free Imperial Cities are one-province republics granted special favors by the Emperor. The game begins with the maximum number of Free Cities in the HRE. In the chance that number decreases, the emperor may appoint new ones (if the proposed nation accepts) as needed up to the maximum number of 12 Free Cities. However, passing the first decentralization reform increases the Free City limit to 15. For every Free Imperial City, the amount of Imperial Authority is increased by +0.005 monthly, and the Emperor also receives +2 annually for each city. In return, they get a special government type (breaking any pre-existing Royal Marriages with no penalty), and the Emperor is always called into war if a Free City is attacked, even if the attacker is in the Empire and has a valid Casus Belli. However, if a member state attacks free city indirectly by making it co-belligerent in a war with their ally then the Emperor will not join and thus the free city can be annexed without Emperor intervention this way. If the emperor attacks a free city, it will suffer −3 stability.

At the start of the game, the Free Imperial Cities are:

Aachen
Bremen
Dortmund
Frankfurt
Goslar
Hamburg
Konstanz
Memmingen
Nuremberg
Ulm
Regensburg
Rothenburg

As with electors, the empire functions properly with them at their max number. The AI will always grant the status of Free City to the maximum of 12, as long as there are 12 eligible nations.

To offer Free City status to a nation, these requirements must be met:

If a nation qualifies, other factors such as diplomatic reputation, trust, and government type will affect the offer of becoming a Free City. In particular, republics are much more willing to become Free Cities than monarchies or theocracies.

Any Free City that loses its status becomes an Oligarchic Republic. A Free City loses its status under any of these conditions:

Unlawful territory

Unlawful territories are provinces that are a part of the HRE, but are owned by a Christian country that does not have a core on them. This applies even if the owner is a member of the HRE.

Liberating territory from a non-HRE member that controls HRE territory will not allow for the emperor to demand it. For example, if Burgundy takes over territory on the eastern HRE front, and the player then reconquers that territory from Burgundy, the player will not get unlawful territory. If the player were to conquer that land before Burgundy it would be considered unlawful.

The HRE emperor may request the owner of unlawful territory to return the province to an HRE member that has a Core on in (note this may not be its original owner). Being allied with positive opinion to the emperor makes it less likely that he will demand unlawful territory from a nation. However AI-controlled emperors do not actually demand unlawful territory from countries at war. To exploit this, the player can 'chain' wars back to back and core territory while at war to avoid unlawful territory demands. Also the emperor will get a malus to demand more than one province from one nation so taking two provinces and returning one and keeping the other is another option. However that will of course mean you get AE for both provinces in the peace deal.

Refusing a demand for unlawful territory will reduce relations with all HRE members by −25 and give the emperor an Imperial Liberation casus belli against the target. The province in question will also receive the following penalties for a duration of 10 years:

The nation holding the unlawful territory also receives the following penalties for each un-cored province:

Imperial reforms

The Emperor with the support of enough member states may attempt to pass imperial reforms. The sequence of centralization reforms in the game is loosely based on proposals that were made in the historical Holy Roman Empire starting in the 15th century, in order to "reform" it back into the more centralized and efficient structure it was considered to be in the 10th-12th centuries. Such reforms would have shaped it into something more like the conventional nation-states of the rest of Europe. They were usually promoted by smaller members and the Emperor, and opposed by Empire's electors and more powerful members.

The threshold for proposing a reform is having 50 imperial authority.^[5] Once the Emperor has more than 50 imperial authority and half of the members' support, for each additional point they gain a boost to the nations' willingness to support said reforms. The Emperor's subject nations will almost always support him. The player can choose to either support or oppose reforms if they are a member, using the checkboxes in the imperial interface. By default the player opposes them.

Very importantly, Reforms cannot be enacted while the HRE is in a state of religious war (i.e. simply the existence of the religious leagues will disallow you to enact any reforms). If no war is started against the Emperor (by 1625) by the opposing religion to his then it will take more 30+5 years to dissolve, assuming that the following conditions are also met: no Elector can be (1) of the opposing religion, and (2) be in the opposing league and (3) have a truce with the Emperor (hence stop wars with them). So either win the League War and establish your religion as the dominant one (all non-conforming electors will automatically be removed) or assuming no opposing religious league ever attacks the Emperor in a religious war then fast-track the process by destroying any Elector, even if the same religion as the emperor, if they are in the opposing league or simply have no wars with them to let the truces expire. Otherwise one would still be paralyzed into not being able to pass reforms even 120 years later and deep into the Age of Absolutism. Not knowing this last rule is why many say the league war mechanic is broken, when it is really just not well explained.

Princes (i.e. members) may either support or oppose the Emperor's reforms due to:

Reason	Modifier
Economic power	−0.1 per development
Same government type	Monarchies: +2 with other monarchies
	Theocracies: −5 with other theocracies
	Republics: neutral
Opinion	+10% of positive opinion of the Emperor (i.e. +20 at +200 opinion)
Opinion	−50% of negative opinion of the Emperor (i.e. −100 at -200 opinion)
Heretic	−20 if the prince's religion is considered heretical by the Emperor
Heathen	−50 if the prince's religion is considered to be heathen by the Emperor
Subject of Emperor	+25
Overextension	−25% of the emperor's current overextension (i.e. −25 at 100%)
Alliance with the Emperor	+5
Same dynasty as the Emperor	+3
Different culture	−5 for different culture in the same culture group
Different culture	−10 for culture in a different culture group
Imperial Authority	+1 for each point of Imperial Authority above 50
Previous reforms passed	−3 for each previous reform
Diplomatic Reputation	+5 for each point of diplomatic reputation
Weak emperor	−2 for each point of total development of the Emperor's provinces less than 100, taking local autonomy into account
Libertas Ecclesiae	+15 if the prince is catholic while the Golden bull "Libertas Ecclesiae" is active.
If a prince is human	Human is for: +100 .
	Human is against: -100 .
	All other modifiers are negated.

List of reforms and their effects

Imperial reforms are split into three types, common, centralization, and decentralization. Common reforms, shown in the top row of the HRE interface, can be passed regardless of whether centralization or decentralization reforms have been selected, and must be passed in order to choose one of the two. Centralization and decentralization reforms, meanwhile, are mutually exclusive, unlocked after passing the reform Perpetual Diet, and either unite the HRE into a unified state or empower individual princes. Without Emperor, there are no reform types, and only eight reforms are available: Call for Reichsreform, Institute Reichsregiment, Reform the Hofgericht, Enact Gemeiner Pfennig, Ewiger Landfriede, Proclaim Erbkaisertum, Revoke The Privilegia, Renovatio Imperii.

Reform	Emperor	Princes/Empire Provinces	Type	Required Reform	Notes
Call for Reichsreform	"Imperial Ban" casus belli against non-members with Imperial territory	−5% Construction cost in every Empire province −5% Development cost in every Empire province	Common reform	None
Institute Reichsregiment	+1 Diplomats +1 Diplomatic reputation	−2 National unrest in every Empire province	Common reform	Call for Reichsreform
Absolute Reichsstabilität	Gives casus-belli on non-members bordering the Empire to force them to join the Empire.	−25% Local state maintenance in every Empire province	Common reform	Institute Reichsregiment
Enact Gemeiner Pfennig	+0.5 Yearly tax income per Prince +1 Diplomatic reputation	+1 Diplomatic reputation for Prince	Common reform	Absolute Reichsstabilität
Perpetual Diet	+50% Imperial authority from free cities	None	Common reform	Enact Gemeiner Pfennig	A random HRE province that: Is owned by Free City Is the capital of an Elector and has at least 20 development Is a Prince's capital and has at least 30 development Is one of the following provinces: Regensburg (2957) Augsburg (1868) Ulm (1872) The owner of this province gets the province event "Perpetual Diet" This province gains the triggered province modifier "Perpetual Diet"
Create the Landsknechtswesen	−25% HRE mercenary recruitment cost	−25% HRE mercenary recruitment cost	Common reform	Perpetual Diet
Ewiger Landfriede	−5% Technology cost	−5% Technology cost for every Prince	Common reform	Create the Landsknechtswesen	Princes may not declare war on one another (a non-member Emperor is not affected). Present wars are unaffected, and members may still be called into wars against other members. Co-belligerents, however, will not call their Imperial allies against an Imperial foe.
Establish the Reichstag Collegia	+3 Number of free cities	None	Decentralization reform	Perpetual Diet	Mutually exclusive with 'Reform the Hofgericht'
Expand the Gemeiner Pfennig	+100 Manpower increase per prince	+200 Manpower increase for electors per prince +10% Local friendly movement speed in every Empire province	Decentralization reform	Establish the Reichstag Collegia
Embrace Rechenschaft Measures	+1% Imperial authority growth modifier per Prince over 25 +1 Number of electors	None	Decentralization reform	Expand the Gemeiner Pfennig
Geteilte Macht	None	+0.5 Yearly tax income for Electors per Prince −5% Local development cost in every Empire province	Decentralization reform	Embrace Rechenschaft Measures
Reichskrieg	None	None	Decentralization reform	Geteilte Macht	Allows the Emperor to create a Casus belli on any nation not currently in the Empire. The Emperor and Electors will be able to raise War taxes for free while at war with enemies of the Holy Roman Empire. Reichskrieg costs 25 IA to use and can only target countries bordering HRE with more development than the Emperor.
Reform the Hofgericht	−10% Core-creation cost	None	Centralization reform	Perpetual Diet	Mutually exclusive with 'Establish the Reichstag Collegia'
Curtail the Imperial Estates	+25% Imperial authority growth modifier per Prince over 25	None	Centralization reform	Reform the Hofgericht
Proclaim Erbkaisertum	+25% Imperial authority growth modifier Will remain Emperor on all further successions No longer gains +10 Imperial Authority on succession Subject princes do not use diplomatic relation slots.	None	Centralization reform	Curtail the Imperial Estates	There are no more elections for Emperor. Electors no longer vote, though they retain Elector status. Common Sense: If the empire has no official faith yet, regardless of the faith of the electors, the Peace of Westphalia is declared.
Revoke the Privilegia	+25% Imperial authority growth modifier	−10% Stability cost modifier	Centralization reform	Proclaim Erbkaisertum	Every prince gets the event 'Privileges Revoked' with the following effects: Princes who support the reform become vassals of the Emperor. Other relations, such as Personal Unions, will be dropped if they conflict with becoming the Emperor's vassal. This will likely cause non-HRE vassals to become disloyal, as total military strength will increase greatly. Princes who do not support the reform will leave the Empire, receive −100 relations with the Emperor, and the Emperor gains temporary claims on the provinces that were in the Empire. Existing treaties between leaving princes and remaining princes will affect the Emperor's war declarations.
Renovatio Imperii	The event "Renovatio Imperii Romanorum" happens	None	Centralization reform	Revoke the Privilegia	All princes are inherited by the Emperor The Holy Roman Empire interface is disabled.

Notes and strategies for specific reforms

Ewiger Landfriede

It is still possible for princes to end up at war as a result of honoring alliances with non-members or intervening in succession wars.

Revoke the Privilegia

When playing as the Emperor, in order to get as many princes as possible as vassals, it is worth increasing Imperial Authority to a level where all or most members would vote yes for this reform. Try distributing gifts, royal marriages, alliances and other relation-improving maneuvers to members who oppose it, before implementing the reform. Once passed, if a new vassal is engaged in war, as the vassal overlord the emperor will take control, but be aware that this includes wars with belligerents both outside and inside the Empire, which may mean that instead of becoming overlord of a HRE province the player declare war on it, even if it agreed to the reform. Ewiger Landfriede means this should not happen too often, but it's something to be aware of.

Due to the previous reform, the vassal relationships gained as a result of this decision do not count towards diplomatic upkeep. If the Emperor releases a vassal within HRE territory as an Imperial Prince, the newly released vassal will not count towards diplomatic upkeep either. A nation liberated after this reform, however, will not automatically become the Emperor's vassal.

Passing this reform also changes the way that vassal liberty desire is calculated. Before the reform, each vassal's liberty desire reflects the combined strength of all vassals, in or out the HRE. After the reform, an HRE vassal's liberty desire no longer take into account his strength or those of the other vassals. Beware, however, that non-HRE vassal will still take into account the strength of HRE vassals (as that of other vassals), which can lead to a sudden rise in non-HRE vassal's liberty desire when the reform is passed.

This reform is where the HRE will be the strongest, as any country that the emperor declares war on will have a large swarm of vassals to fight through. If the Empire is strong enough, they can usually take most (if not all) large Eurasian nations, even without any allies (providing the vassal swarm is large enough). A common strategy when playing as Austria and having revoked the privilegia is to rotate between targets. Attacking (in no particular order) the 3 countries that have been listed above will keep the player's army and navy tradition high and allow him/her to recruit better and better generals as time progresses. When playing as an expansionist Austria (which is recommended most of the time), it is prudent to feed captured land to vassals to make them even stronger, giving eastern land to, for example, Pomerania, Brandenburg, and Bohemia and western land (France, Spain/Castile, and maybe even Northern Africa) to the small vassals in the western part of the Empire, and taking the Ottomans, the Black Sea, and nearby steppes for the player or giving it to other members.

If Art of War is enabled, consider designating your HRE vassals as marches if you don't need their territory and have a strong economy, as it will lower their liberty desire (so you can feed them even more), and strengthen their military abilities, making the swarm even more unstoppable.

Renovatio Imperii

The last reform will consolidate all member states of the HRE into a true, unified nation, with the emperor becoming its ruler. This reform is easy to pass, as all the remaining HRE states are now vassals and will usually vote for it. This has a very, very negative impact on relations with former HRE members who left when the player revoked the privilegia - they get a special "Unified the Empire" -100 relation penalty with the emperor. In addition, there will be a lot of aggressive expansion when trying to conquer their provinces. Note that the cores the emperor gets on imperial territory of non-members will not include those that left as a result of the previous reform, since that reform already removed all of their provinces from the empire.

Even if the player did everything right and made it this far by being nice and defending any and all princes (even the ones who insulted and backstabbed the emperor for centuries), it's quite likely the player will actually be weaker after uniting the empire since HRE bonuses are lost upon enacting the decision. Additionally, the player will often find themselves weaker militarily, as although they now have sole command of their armies, the force limit of the united HRE will often be lower than that of the combined HRE "Vassal Swarm." Beware that when the empire is united, all armies and navies under the command of the HRE Princes are passed on to the unified HRE, which can be devastating to finances due to being over the force limit. The player may need to disband a significant portion of their inherited military units. However, the unified HRE should still emerge vastly stronger than the emperor's original nation and may outnumber the militaries of even a strong Ottoman or France.

If done right, uniting the HRE can be fun and rewarding, and will additionally net the player the "A Kaiser not just in name" achievement if playing on Ironman. If the player has managed to keep imperial territory out of non-imperial hands, expand the empire both in number of provinces and princes, and skillfully navigate the military and diplomatic trials, they may become the dominant nation in Europe or even the world.

Dismantle HRE

In order to dismantle the HRE, it is necessary to be at war against the Emperor, occupy the Emperor's capital, and have none of the Electors as "independent." Whether an Elector is counted as "independent" is not determined by whether they are independent or subject nations. The conditions are:

If the Elector is independent and does not join the war, it is "independent."
If the Elector is allied to the war leader against the Emperor, it is "not independent."
If the Elector is a vassal of the war leader against the Emperor, it is "not independent."
If the Elector is a vassal of someone other than the war leader, and does not participate in the war fighting against the war leader, it is "independent."
If the Elector is a vassal of the Emperor, the Elector is "not independent" if their capital is captured.
If the Elector is independent, and at war with the war leader (can be a separate war), the Elector is "not independent" if their capital is captured.
If the Elector is a vassal of any country other than the Emperor or the war leader, it is "independent."

The tooltip for the Dismantle HRE button in the HRE interface will tell you which Electors are currently counted as "independent".

In order to dismantle the HRE, it is helpful or even necessary to either ally with or vassalize as many of the Electors as possible. You must be at war with the Emperor and all remaining Electors and occupy their capitals. These can be multiple wars. Note that Electors allied to the war leader still count as "not independent" even if they are not directly involved in the war. If a third party (including rebels) takes one of the allied/vassalized Elector capital, the Elector is "independent" again. Importantly each capital of the Emperor and enemy Electors must be controlled by you, so if an ally sieges even one capital down without transferring occupation to you the HRE cannot be dismantled. Simply marking the target elector capital as territory of interest is not sufficient, try and bee-line to each and siege the capitals down yourself.

Dismantling the HRE will grant +100 prestige to the war leader, and remove the HRE interface altogether. Also modifier for religion which won league war will be removed.

In addition, the HRE will automatically be dismantled if there is nobody eligible to be elected Emperor (see above for requirements).

In order to be dismantled the empire must have at least one elector. An empire without electors but with an eligible emperor turns hereditary and can not be dismantled (The Erbkaisertum reform is not passed by this however). This can happen lategame if all member states have converted to non-Catholic religions but the AI did not start the League War, leading to a Catholic emperor without eligible electors.

Imperial incidents

Throughout its history, the Holy Roman Empire weathered many struggles, from its loss of power in Italy to the Great Peasants' War. In game, these major events are represented as imperial incidents, large events that affect equally large parts of Europe. Every member of the HRE can support a certain outcome on an incident, and after one year the outcome is decided by the Emperor. However, choosing an outcome for an incident that is not popular with most of the HRE carries strong penalties. The Emperor gains 0.2 Imperial authority per prince supporting the outcome that was chosen, and 1 Imperial authority for every elector supporting that outcome. Meanwhile, the Emperor also loses the 0.2 and 1 Imperial authority for every Prince and Elector supporting the most supported outcome that was not taken. Below is a list of all imperial incidents. Unless it fulfills one of the criteria for selecting an outcome, outcomes are randomly chosen by Princes and Electors

Name	Trigger	Outcomes	Stop Conditions
The Burgundian Inheritance	Burgundy selected the option 'The [Emperor.Monarch.Dynasty.GetName] Prince will do nicely.' in the event "The Burgundian Succession"	Make concessions to France. Integrate Burgundy into the Empire. Keep our union with Burgundy.	Burgundy does not exist
The Burgundian Inheritance (Strong ally)	Burgundy selected the option '[bur_strongest_ally.GetName] will defend us again.' or 'Let us reintegrate with the French.' in the event "The Burgundian Succession"	Demand lowland independence. Press our claim on Burgundy. Abandon the claims.	Burgundy does not exist
The Burgundian Inheritance (Alone)	Burgundy selected the option 'Come what may, Burgundy shall remain Burgundian.' or 'The French aren't here to stop us anymore.' in the event "The Burgundian Succession"	Demand lowland independence. Press our claim on Burgundy. Abandon the claims.	Burgundy does not exist
Burgundy and the Empire	Burgundy selected the option 'I never much cared for claiming the French Throne.' in the event "Imperial Entrance"	Welcome [BUR.Monarch.GetName] of [BUR.GetName] into the Empire. AI will always choose this option if it has one of the following attitudes towards Burgundy: Friendly Loyal Allied Ban their entry. AI will always choose this option if: it is a neighbor of Burgundy but not allied to Burgundy it has one of the following attitudes towards Burgundy: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: Burgundy does not exist Burgundy is the Emperor of the HRE Burgundy is a subject nation
The King in Prussia	Prussia selected the option 'We shall be Kings' in the event "A Prussian Crown"'	Elevate Prussia to an Imperial Kingdom. AI will always choose this option if it has one of the following attitudes towards Prussia: Friendly Loyal Allied Let [PRU.Monarch.GetHerHim] call [PRU.Monarch.GetHerselfHimself] the King in Prussia AI will always choose this option if it has a Neutral attitude towards Prussia We will not recognize this self-appointed monarch. AI will always choose this option if it has one of the following attitudes towards Prussia: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: Prussia does not exist Prussia is a subject nation Prussia is a Kingdom
Petition for Membership	A Prince selected the option 'We shall take this to the Imperial Diet.' in the event "Petition for Membership"'	[current_pu_incident_target.GetName] shall join the Empire. AI will always choose this option if one of its subject nations has the country flag `current_pu_incident_target_flag` We do not accept this application.	One of the following must be true: No country has the country flag `current_pu_incident_target_flag` Any country that has the country flag `current_pu_incident_target_flag`: One of the following must be true: Is not a subject nation This country's overlord is not a member of the HRE
The Fate of the Peasantry	The event "The Great Peasants' War" has happened	Crush the remaining agitators. AI is 10 times more likely to choose this option if Nobility influence is at least 60 Grant concessions to the peasantry. AI is 10 times more likely to choose this option if one of the following is true: Nobility influence is less than 40 it is Reformed AI is 1000 times more likely to choose this option if it has enacted Peasants Republic	None
Decline of the Hanseatic League	Lübeck selected the option 'Ask the Emperor for help.' in the event "Decline of the Hanseatic League"	We have no obligations to the Hansa. AI will always choose this option if it has one of the following attitudes towards Lübeck: Rivalry Hostile Threatened Outraged Disloyal Rebellious Organize the Free Cities to help. AI will always choose this option if it has one of the following attitudes towards Lübeck: Friendly Loyal Allied Declare an embargo against [lubeck_trade_power.GetName]. AI will always choose this option if the strongest trade power in the Lübeck trade node has one of the following attitudes towards it: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: Lübeck does not exist Lübeck is not a member of the HRE Lübeck has not enacted Oligarchy
The Pope and the Emperor	The Papal States selected the option 'We will join the Empire.' in the event "A Holy Empire?"	The Pope will join the Empire AI will always choose this option if it has one of the following attitudes towards the Papal States: Friendly Loyal Allied The Holy See should remain independent. AI is 50 times more likely to choose this option if one of the following is true: It is excommunicated It is not Catholic AI will always choose this option if it has one of the following attitudes towards the Papal States: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: The Papal States do not exist The Papal States are a subject nation
The Question of Holstein	The Emperor of the HRE selected the option 'This matter requires deliberation.' in the event "The Question of Holstein"	Demand the restoration of Holstein. AI will always choose this option if it has one of the following attitudes towards the owner of Holstein (1775): Rivalry Hostile Threatened Outraged Disloyal Rebellious Relinquish the Imperial claim. AI will always choose this option if it has one of the following attitudes towards the owner of Holstein (1775): Friendly Loyal Allied	One of the following must be true: Holstein exists The owner of Holstein (1775) is a member of the HRE
The Shadow Kingdom	The Emperor of the HRE selected the option 'The Emperor must decide. Summon the diet!' in the event "The Shadow Kingdom"	It is time to abandon Italy. AI is twice as likely to choose this option by default AI is five times more likely to choose this option if its capital is in the Italy region We must rein in the Italians.	None
Switzerland and the Empire	Switzerland selected the option 'We no longer need the Empire.' in the event "Switzerland and the Empire"	Grant them permission to leave. AI will always choose this option if it has one of the following attitudes towards Switzerland: Friendly Loyal Allied Membership is not optional. AI will always choose this option if it has one of the following attitudes towards Switzerland: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: Switzerland does not exist Switzerland is the Emperor of the HRE Switzerland is a subject nation Switzerland is a member of the HRE Switzerland is at war with the Emperor of the HRE Switzerland is in a defensive war together with the Emperor Switzerland is in an offensive war together with the Emperor
The Dutch Rebellion	The disaster Dutch Revolt is happening	We will support the Dutch. AI will always choose this option if it has one of the following attitudes towards the Netherlands: Friendly Loyal Allied We should not intervene. AI will always choose this option if it has a Neutral attitude towards the Netherlands They are rightful subjects of [dutch_revolt_country.GetName]. AI will always choose this option if it has one of the following attitudes towards the Netherlands: Rivalry Hostile Threatened Outraged Disloyal Rebellious	One of the following must be true: Netherlands does not exist The Netherlands is at peace The Netherlands is at war with the Emperor of the HRE
Hungary Wishes to Join the Empire	Hungary selected the option 'Hungary belongs in the Empire.' in the event "Membership in the Empire"	Hungary's membership would strengthen the Empire. AI will always choose this option if it has one of the following attitudes towards Hungary: Friendly Loyal Allied Hungary's membership would damage the Empire. AI will always choose this option if it has one of the following attitudes towards Hungary: Rivalry Hostile Threatened Outraged Disloyal Rebellious	No country has the country flag `hungary_incident_flag`
The Reformers Protest	The Emperor of the HRE selected the option 'A black day!' in the event "The Evangelical Union is Victorious"	The Empire is and will remain Protestant! AI is 50 times more likely to choose this option if it is Protestant Grant them equal rights. AI is 50 times more likely to choose this option if one of the following is true: it has enabled humanist ideas it is Catholic We must concede to all demands. AI is 100 times more likely to choose this option if it is Reformed AI will never choose this option if it is not Reformed	None

Religious leagues

HRE interface while it's "in a state of religious war", with the league leaders and members on each side.

At the start of the game in 1444, a ruler can only be elected Emperor if they follow the dominant religion - Catholic. However, Electors can be of any Christian religion. After 1550, if one of the Electors (that is not a subject nation) has become Protestant, Reformed, Anglican, or Hussite and the Empire hasn't been reformed to the point of becoming hereditary, then the religious leagues can be formed by the event The Evangelical Union. Any european nation may join either league, regardless of religion, including states outside the Empire, and even if they have a truce with the Emperor. The Catholic League will begin with the current Emperor at the head, any subsequently elected emperor will automatically assume leadership of the Catholic league, even if they had previously been neutral or part of the Protestant League. The Protestant League is headed by the first protestant country which joins, thereafter the leader is determined based on a military score determined by the nations maximum manpower, force limit, and tactics. Being at war reduces a country's military score by 80%, while being an elector boosts this score. Only Protestant countries are eligible to be league leader, this excludes other denominations entirely (e.g. Reformed, Anglican, Hussite).

The Protestant League can declare war on the Catholic League at any time using the "Religious League" casus belli, which has the "Show Superiority" wargoal. If a league leader is attacked by any nation during a league war, their fellow league members will automatically join the war as defenders of the leader. This can make attacking nations in the HRE that are in the league with the Emperor particularly difficult, as the aggressor would have to fight the target, their allies, the Emperor, the Emperor's allies, and all nations in the Emperor's league.

If a member of the Protestant League is already at war with the Emperor when the league war is declared, they are not called into the league war and their own war against the Emperor continues as normal.

Joining a league war grants the "Joined League War" country modifier for 100 years from the start of the war, which gives the following benefits:

If a league wins the war by enforcing the "Religious Supremacy" peace term for 50% war score, that league will have their religion made the permanent official religion of the Holy Roman Empire. This disables further league wars and means that only countries of this religion can become electors or emperors. Furthermore, all countries with their capitals in Europe, even if outside the Empire, will gain the following benefits if they follow the victorious religion:

If the protestant league enforces "Religious Supremacy", but the HRE is predominantly reformed, the incident "The Reformers Protest" will happen which can make reformed the official faith.

If any league war lasts a long time (25 years), or if it ends in a peace that does not involve either side securing the "Religious Supremacy" peace term, the Peace of Westphalia is signed, ending the religious war and allowing any Christian to be elected Emperor. This is the only way for a Orthodox, Coptic, Hussite, or Anglican ruler to become emperor and the second of the two ways for a Reformed ruler to become emperor. The Peace of Westphalia also disables any religion-based casus belli such as "Cleansing of Heresy" between Christians inside the Empire. Emperors will no longer gain or lose imperial authority for Princes converting after the Peace of Westphalia is signed, also the monthly imperial authority loss for heretic princes is halved.

If the religious leagues are not triggered in the HRE before 1625 or if the leagues form, but the war is not declared for 30 years, the event The Diet of $CAPITAL_CITY$ can happen for the emperor and declare catholic the official faith of the empire. This event ends the leagues if they had formed. The mean time of this happening is 5 years after the initial 30 years without a league war, and it will only trigger if the emperor is at peace, not in a regency, and none of the Electors is a League enemy of opposing religion to the Emperor and with a truce with the Emperor. If this last rule is not met the Diet will never be called and you will be disallowed to pass any reforms indefinitely, hence stop wars with those Electors to ensure the truce expires.

Missions

Main article: Imperial missions

Mission event

Crowned by the Pope

We have reached a final and permanent accord with the Vicar of Christ, Pope [PAP.Monarch.GetName]. From this day forth, the Holy Father will personally crown the Holy Roman Emperor.
An agreement has also been reached in which the Emperor will have de facto primacy over the Church within the Imperial domain, bringing an end to centuries of often violent disputes between Pope and Emperor.

Trigger conditions None	Is triggered only by the mission "Roman Resolution"
We are truly a Roman empire.

Conquering provinces in the HRE

Conquering provinces in the HRE and from HRE members presents four potential additional hurdles: a 50% penalty to fabricating claims, the Emperor being called in the war, the provinces being demanded back as "unlawful territory", and 50% increased aggressive expansion when taking HRE provinces.

Emperor being called in wars against HRE members

The emperor will receive a call to war as a cobelligerent if you attack an HRE Free City, attack a member as a non-member, or attack a member with no casus belli.

How to handle:

Declare war on a non-HRE ally of the HRE member you want to conquer and don't name the HRE member as a cobelligerent
Use Enforce Peace, Proclaim Guarantee or possibly Great Power intervention to join a war involving an HRE member
Get yourself or an ally attacked by an HRE member
Vassalize diplomatically instead
Attack an HRE member at war with the Emperor
Join the HRE
Attack when the Emperor is unlikely to heed the call to arms (depleted army and manpower, in other wars, you being strong, emperor's rival)
Be stronger than the Emperor and just fight him (or possibly have him decline the call the arms because he's afraid of you)
Become the Emperor
Dismantle the HRE

Note that having an alliance with the Emperor does not help, as they may still join on the defender's side.

Emperor demanding back non-cored HRE provinces

Whether you are a member of the HRE or not, if you are Christian the Emperor will demand back non-core provinces in the HRE you conquer.

How to handle:

Vassalize militarily or diplomatically instead
Have an alliance and good relations with the Emperor (ideally at +100 improvement)
Be in another war while you take and core the province. While the Emperor can demand unlawful territory while you are at war (not with him), AI-controlled Emperors don't seem to do so
Decline and take the penalties and Imperial Casus Belli
Take and core the province when the Emperor is at war. While the Emperor can demand unlawful territory while he is at war (not with you), AI-controlled Emperors don't seem to do so
Take and core the province while the Emperor has a long truce with you. The Imperial Liberation CB expires in 10 years.
Become the Emperor
Start as a non-Christian country, or convert to a non-Christian religion
Dismantle the HRE

Reforms

If Call for Reichsreform has been passed, the Emperor will have a casus belli on non-members holding HRE provinces.

If Ewiger Landfriede has been passed, HRE members can't declare war on other HRE members.

If Absolute Reichsstabilität has been passed, the Emperor will have a casus belli on borderding non-members to force them to join the HRE.

Revoke the Privilegia and Renovatio Imperii cause would-be conquerors to be at war with the whole HRE.

Historical context

The Holy Roman Empire was the dominant political power in Central Europe during this historical period. Compared to earlier centuries, when the Emperor wielded more control over his territory, the Empire by the EU4 timeframe had become greatly decentralized, and its member states acted with great autonomy. The power of the Emperor was still considerable. He had the power to intercede in the wars and affairs of the member states of the Empire. If the Emperor can enact the reforms, he can eventually centralize all the separate nations of the Empire under his own banner, and turn the Holy Roman Empire into a unified powerhouse which in the right hands can be almost unstoppable. Alternatively, the Empire can wane in power, and, as happened historically in 1806, it can eventually be dismantled. In game, however, the Holy Roman Empire usually passes a moderate number of reforms. What happens largely is the elimination of most one province minor states and leads to an end game scenario of 8-18 mid-sized states instead of the original 50.

Achievements

A Kaiser not just in name icon

Form the Holy Roman Empire.

Electable! icon

Become an elector in the HRE as a country which does not start as elector.

The Emperors new clothes icon

Overthrow Austria and become the Emperor of the Holy Roman Empire.

Everything's Coming Up Mulhouse icon

Starting as Mulhouse, become Emperor of the HRE and completely decentralize the Empire.

Holiest Roman Empire icon

As either the Papal States or the Emperor, have the Papal States as an Elector while the HRE is officially Catholic.

Neither Holy, Nor German icon

Have 7 Free Cities in the Empire, none of which is of a Germanic culture.

Voltaire's Nightmare icon

Have at least 100 countries in the HRE.

External references

Development Diary 22: A.E.I.O.U

Footnotes

↑ See in /Europa Universalis IV/common/static_modifiers/00_static_modifiers.txt (Static modifiers#Emperor).
↑ See in /Europa Universalis IV/common/static_modifiers/00_static_modifiers.txt (Static modifiers#States in the Holy Roman Empire).
↑ See in /Europa Universalis IV/common/static_modifiers/00_static_modifiers.txt (Static modifiers#Free Cities in the Holy Roman Empire).
↑ ^4.0 ^4.1 this number is calculated as IMPERIAL_AUTHORITY_FROM_PRINCES / HRE_PRINCE_AUTHORITY_THRESHOLD. These values can be found in /Europa Universalis IV/common/defines.lua
↑ See in /Europa Universalis IV/common/defines.lua.