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Subject nation

(Redirected from Tributary)
The subjects interface panel image as of patch 1.18

Subject nations are semi-independent subordinate nations that surrender their economic, diplomatic and/or military power to another country in exchange for protection by their overlord. It is possible to see a subject's nation information by selecting the country icon on the subjects tab. The types of subject nations range from the primarily economic Subject tradecompany icon.pngTrade company to the military-focused March icon.pngMarch. All subjects (except trade companies) have a Liberty desire.pngliberty desire that determines their loyalty towards their liege.



Main article: Vassal

  Vassals are the most basic form of subject nations. They are required to pay a portion of their  tax income to their overlord but do not transfer  trade power to their overlord like other particular subject types(vassals of a merchant republic transfer 50% of their trade power to their overlord if   Wealth of Nations is active). While vassals may have control over their own territory and military, they also automatically join any conflict their overlord enters into.

Vassalization can occur militarily by forcing it upon a defeated enemy in a war. Diplomatic vassalage can occur if a military alliance exists and relations are high (above 190). Vassals cannot declare war, but can fabricate claims that either they or their overlord deems as 'Vital Interest'. Vassals with over 50%  liberty desire can request a support of independence from other nations, and break free through an independence war. Vassals with over 50%  liberty desire are also more active diplomatically as to forming their own alliances with other rebellious subjects of their overlord and setting more provinces as those of interest.

After a nation has been a vassal of another country for at least ten years, their overlord can begin diplomatically integrating them into the overlord's domain. This results in the vassal's annexation.


Main article: March

A   march is a militaristic vassal that cannot be annexed and does not pay taxes to the overlord, but has lower liberty desire and gets significant bonuses to its armed forces.

Marches receive increased  land and  naval force limits,  manpower and  manpower recovery speed, and  fort defensiveness, while also gaining decreased  fort maintenance.

March status can be revoked and the subject turned into a simple vassal but at the cost of stability and relations loss.

Without the DLC, marches can only be gained through special events, such as the subjugation of   Moldavia to   Poland.

Client stateEdit

Main article: Client state

Client states are highly loyal, custom vassals. They can be formed once a country reaches   diplomatic tech level 23 from any province or provinces that the player has control over.

Generally, any province within two tiles by land can be added to a client state, including over straits. The first province that a new client state is given is automatically designated as the capital, and the  culture in that province will become the primary culture of the new client state. The client state will have its creator's state religion.

It is possible to customize the flag and the name of a client state based on a set of flag templates and images.

Nevertheless, if you make your client state into a march, customization (such as flag, name, map color) won't be available until you convert it back to vassalization.

Personal unionEdit

Main article: Personal union

Junior partners in a personal union share the same ruler as that of the leading country. Like vassals, junior partners of a personal union will automatically go to war if their overlord does, but they do not have to provide their overlord with a percentage of their monthly income, and only get a small +10   relations boost with their overlord. The junior retains any subjects it had, except other unions, which the overlord inherits.

Personal unions can occur when a ruler dies without a legal heir. In this case, if a royal marriage partner shares the same dynasty as the deceased ruler, it becomes the senior partner in a union. A succession war may erupt between rivals or valid partners. Additionally, a claim throne casus belli can be used on nations with a disputed succession (weak or no heir) of the same dynasty that the player has a royal marriage with.

Personal union partners can be inherited or integrated provided the union has been stable for fifty years. Diplomatic integration annexes the junior partner at the cost of  diplomatic monarch points. Inheritance automatically annexes the junior partner with no autonomy, but occurs only upon ruler death. The probability of inheritance increases with the senior partner's  diplomatic reputation and stability and decreases with the junior partner's number of provinces.

A personal union can end upon the death of the senior ruler when the junior partner has a negative opinion of its senior. If this occurs, the former senior partner will get a "Restoration of Union" casus belli on the former junior partner, allowing the union to be reinstated militarily.

Some nations can get a "Restoration of Union" CB against countries that they never had a union with in the first place, such as Austria, which can receive this casus belli against Bohemia and Hungary as a mission.

Only nations that have one of the Christian denominations as their state religion are able to form personal unions.

Colonial nationEdit

Main article: Colonial nation

  Colonial nations represent the distant New World colonial territories of European powers. They will automatically form once five cored colonial provinces exist inside a single colonial region. Once formed, colonial nations will take control of any province that would otherwise be owned by their overlord in a given colonial region, even if the province is uncored or would otherwise cause extreme  overextension.

Colonial nations pay a portion of their  tax income to their overlord, based on the tariff efficiency. Additionally, colonial nations transfer 50% of their   trade power to the overlord.

When created, the colonial nation's flag is generated based on the mother country's flag and the colonial region the new Colonial Nation is located in. For example, a nation in the Mexico colonial region will have a yellow flag, while one in the Eastern North America colonial region will have a light-blue one.

Trade companyEdit

Main article: Trade company

A   trade company is a collection of overseas provinces that exchanges tax and manpower for trade, maritime and production benefits.

A province in a trade company provides approximately half the  income, no  manpower, and no  sailors to the home country but produces double the  trade power and adds 0.5   naval force limit. Additionally,  goods produced remains unaffected by cultural intolerance, religious intolerance is ignored, and the province does not contribute to   religious unity.

Trade companies may be formed by nations that own at least one province in any of the 15 trade company regions scattered throughout Africa and Asia. As of version 1.30, this restriction no longer applies, and any province in a territory which is on a different subcontinent from one's capital and not in a colonial region is eligible to become a trade company. They differ from colonial nations in the Americas and Australia in that they are not separate governments, as all territories remain part of the mother country. Provinces in trade company must belong to a territory - adding them to a state will automatically remove them from a trade company, which entails the same -200%  goods produced modifier which manually removing one does. Provinces can be added or removed from a trade company at any time, except when the 5-year  goods produced modifier for removal is present.


  Tributaries are a loose form of subject relationship available to nations in the Eastern religion group, as well as to steppe hordes and the Emperor of China regardless of religion. Tributaries retain full diplomatic independence and may start wars and have subjects of their own. The overlord receives a call to arms if the tributary is attacked (unless if by another tributary of the same overlord), but does not have to accept. Each year, the overlord may demand a tribute of   money,   manpower, or any of the 3 types of   monarch points. The tribute is paid annually on January 2. Tribute type demand must be selected before January 1. The default tribute is   money. If the tributary pays the tribute, trust increases slightly; if it refuses, trust falls significantly. AI always pays tribute when   Liberty Desire is below 50% and refuses otherwise.

Monetary tribute is 12.5% of annual income, manpower tribute is 25% of annual gain, and monarch point tribute is 1 per 33   developments (rounded down) and capped at 12 for 400 or more development. If monetary tribute would be below 1 ducat, or monarch point would be below 1 point, they can't be selected. [1]

Either party may renounce the tributary status at will, unless they have a truce. The overlord gets a one-way five-year truce with the former tributary, but the former tributary may attack the overlord immediately. Tributaries who renounce their status lose -1   stability; this can be circumvented by refusing tribute until the overlord breaks the agreement on their own.

The factors that influence an AI nation's desire to accept an   Establish Tributary offer are:

Factor Effect
Attitude towards proposer   Hostile: -1000
   Outraged: -1000
   Rivalry: -1000
   Threatened: +100
Opinion towards proposer +1 per 4 positive points (rounded down)
 -1 per 4 negative points (rounded up)
Proposer's   diplomatic reputation +2 per positive point
 -2 per negative point
AI nation's government rank -20/-100 Kingdom/Empire
AI nation's   development[2] -0.5 per   development (rounded up)
Proposer economic base compared to target nation +90 to -90
Proposer military power compared to target nation +90 to -90
AI nation has subject of its own -1000
Are not neighbors -1000
Distance between borders -0.5 per distance between borders (defunct but still displayed)
Proposer is Celestial Empire or has horde government with rank Empire[3] +10


For a tributary overlord, sending manpower to tributary subjects at war can often be the cheapest way to decrease liberty desire and maintain the more value tribute income in the form of monarch powers. It can thus be helpful to set large tributary countries as "special interest" (right-click on country flag in provincial interface) and receive notification for wars by these tributaries.

For establishing tributary subject of AI nation,   threatened attitude gives the most significant +100. (Strangely,   friendly attitude does not give any modifier.) The attitude goes away at high opinion. Thus the optimal opinion with the threatened attitude is around 0. Player should avoid improving relation for too long in that case.


Main article: Japan#Daimyo & Shogunate

Daimyo are a unique form of vassal for the shogun of   Japan. They may ally with and fight other daimyo, but not foreign countries. They do not occupy a relation slot, and the shogun has several special vassal interactions for them. Note: outside nations can enforce peace on two warring daimyos without calling the shogun or its vassals to war, effectively providing a way for outside powers to get easy land on japan.


In previous versions of the game, technologically backward nations could be made protectorates, which exchanged a transfer of trade power and not being allowed other allies for protection from hostile nations and a discount on technology cost. They did not occupy a diplomatic relations slot. Protectorates were merged with regular vassals in patch 1.20.

Liberty desire.pngLiberty desireEdit

All subject nations have a liberty desire between 0 and 100, indicating their wish for independence.

  • Below 50 a subject state is loyal: it pays taxes/tariffs to its overlord and takes an active part in all wars.
  • Above 50 liberty desire, a subject becomes disloyal, refusing to pay taxes while being unhelpful in wars by only defending its own territory. Disloyal subjects readily accept support for their independence from foreign nations and make alliances with each other, and may declare an independence war if they have sufficient strength. In rare cases, a disloyal subject may still have a Friendly attitude toward its overlord; this means it will not accept requests to support its independence or alliances from fellow subjects, but does not otherwise alter its behavior.
  • At 100 liberty desire, a state is rebellious, and will, at least in theory, declare its independence at the slightest opportunity.

Liberty desire depends on the sum of the following factors:

  • The relative army size of the subject compared to its overlord. There is +75 liberty desire for having 100% of the overlord's forces, scaling proportionately (e.g. +37.5 at 50%).
    • The combined strength of all vassals, marches, and client states is used for their liberty desire.
    • Personal union partners, daimyos, and colonial nations only consider their individual strengths.
    • Additionally, nations allied with or supporting the liberty of a subject nation will have their army strength added to that specific subject. Other subjects will not have their army strength increased, unless their independence is also supported.
  • A base modifier depending on type of subject: −25 for client states, −15 for  marches, +10 for Japanese daimyo; 0 for  vassals,  colonies and  personal union partners.
  • +0.25 per point of development for vassals, client states, and marches.
  • +5 for each level the overlord's   diplomatic technology is behind the subject's.
  • −0.1 for each point of positive relations (max −20), +0.2 for each point of negative relations (max +40).
  • −5 for a   royal marriage.
  • −50 for historical  friends.
  • +50 for historical  rivals.
  • +10 subject nation is a  Steppe nomads.
  • −3 per point of diplomatic reputation.
  • ±0.4 per point of trust below/above 50 (min −20 at 100 trust, max +20 at 0 trust)
  • +1 per point of the overlord's  war exhaustion for colonial nations.
  • −50 if recently defeated in an independence war (decreasing over time).
  • +0.2 for colonies, per point of the colonial nation's  administrative efficiency.
  • +1 for colonies, per point of  tariff rate.
  • −0.5 per   granted province development (sum decreasing over time by 0.1 per month).
  • −5 per each development point improved in subject's province (sum decreasing over time by 1 per year).
  • +1 per each  prestige below 0 (-50  prestige equals +50 liberty desire)

Certain ideas reduce liberty desire in subjects:

  Traditions Ideas Bonuses Policies
  • Influence idea 2: Additional Loyalist Recruitment
  • Ajami idea 7: Shahanshah
  • Berg idea 3: The United Duchies
  • Qara Qoyunlu 5: Freedom with Responsibility
  • Tyrone idea 1: Chief of Irish Kings
  • Plutocratic-Influence: Unified Army Command

Subject interactions Edit

All subject nations are listed in the subjects tab in country interface. Subject interactions require   Common Sense DLC unless otherwise stated. Since tributaries don't exist without   Mandate of Heaven DLC, that is also needed for them. Client states and daimyo are special kinds of vassal and so have the same interactions. Liberty Desire modifiers from most sources, such as events and province defections, decay at 0.1% per month. Toggled liberty desire modifiers (embargo rivals, support royalists, subsidize armies, divert trade, send officers) last until cancelled. Liberty desire from tariffs is permanent.

Interaction Subjects Requirements Effect Notes
  Bestow Gifts  
  •  −15% Liberty desire
  • Overlord pays the subject 6 months of subject's income
  Decrease Tariffs  
  • Costs   25
  •  −1% Liberty desire
  • Adjusts   tariffs by −5%
  Demand Additional Tribute   Subject has less than 50%   liberty desire
  •  +25% Liberty desire
  • Subject pays 3 months of subject's income to the overlord
  Demand Artifacts  
  • Subject has less than 50%  liberty desire
  • Subject has positive   prestige
  •  +25% Liberty desire
  •  +5 Prestige for overlord
  •  −5 Prestige for the subject
  Divert Trade    
  •  +30% Liberty desire
  • Overlord gets 100% of subject's  trade power
  Embargo Rivals         Has at least   1 rival
  •  +5% Liberty desire
  • Subject embargoes overlord's rivals
  Enforce Culture   Subject has less than 50%  liberty desire
  •  +25% Liberty desire
  • Costs   2 per subject's development
  • Changes the subject's primary culture to that of the overlord
  Enforce Religion        
  • Subject has different   religion
  • Subject has less than 50%  liberty desire
  • Subject has   positive relations with overlord
  • Changes the subject's religion to that of the overlord
  •  +50% Liberty desire if subject's religion in the same religion group
  •  +100% Liberty desire if subject's religion in different religion group
Decays by 1% per year (around 0.1% each month)
  Fortify March   Fort is built, paid for by the overlord
  Grant Core/Claim         Core/claim has a land connection with subject or is within one sea zone of subject Core/claim is granted to the subject Requires   DLC
  Grant Province           Province has a land connection with subject or is within one sea zone of subject
  •  −0.5 Liberty desire per province   development
  • Province is granted to the subject
  • Cores of overlord go along with the grant
Requires   DLC
  Increase Tariffs  
  •  +1% Liberty desire
  • Costs   50
  • Adjusts   tariffs by +5%
  Knowledge Sharing         Has embraced at least   1 institution that the subject has not embraced
  • Costs   ducats equal to 10% of subject's income per month (not paid to anyone, unlike the diplomatic action)
  • Subject's provinces gain   +1 per month towards the earliest non-present institution embraced by the overlord
Requires   DLC
  Pay Off Debt           Subject has loans
  • Costs   ducats equal to total value of subject's current debt
  • Subject cancels all loans
  •  −5% Liberty desire per loan paid
  • Requires   DLC
  • Cannot pay off only some loans; must be all
  Placate Local Rulers       Has positive   prestige
  • Costs  −20 Prestige
  •  −10% Liberty desire
  Place Relative on Throne    
  • Overlord and subject are both monarchies
  • Subject doesn't already have the same dynasty
  •  +25% Liberty Desire, or  +10% if subject is in a regency
  • Places overlord's dynasty on subject's throne
  Promote Investments  
  •   +50% Trade power in all owned provinces
  •   +0.03% yearly inflation while active
Requires   or   DLCs
  Replace Governor   Subject has less than 50%  liberty desire
  •  +10% Liberty desire
  • Gives the subject nation a new leader
Choice between 4/2/2, 2/4/2 or 2/2/4
  •  +50% Vassal income
  • Subject will no longer be called to wars
  •  +25% Liberty desire when disabled
  • Disabling it during a war will not call the subject to arms
  • Disabling multiple times will stack the liberty desire increase
  Seize Land    
  • Subject has positive  opinion of overlord
  • Subject has less than 50%  liberty desire
  •  +5 Liberty desire per province   development
  • Overlord seizes province
Cannot seize  capital
  Send Additional Troops   Subject is at war
  •  −10% Liberty desire
  • Send   manpower to the subject equal to 2 years of subject's   manpower recovery
  Send Officers  
  •  −10% Liberty desire
  • Overlord pays 33% of subject's   army maintenance
  • March gets   +20% morale of armies and   +5% discipline
  Siphon Income   Subject has positive   opinion of overlord
  •  +10% Liberty desire
  •   −100 relations with subject
  • Gain   50% of subject's yearly income (as an instant lump sum)
  Start War in Colony   Subject is at peace, has a casus belli against target and no truce with target
  • Subject starts a war with natives or another colonial nation
  • Overlord is not called in
  Subsidize Armies  
  • 10% of the overlord's  manpower is sent to the subject
  •   +50 relations with subject
  Support Loyalists  
  • Costs 10% of the subject's income
  •  −20% Liberty desire

Enhance provinces of subject nationsEdit

It is possible for the overlord to construct buildings in the provinces of subjects, and to develop them to reduce their liberty desire. The more points are spent on the development, the more the subject's liberty desire will be reduced. However, base liberty desire increases with each point of development, so this is a short-term savings that may hurt you in the long run.

Military focusEdit

A nation can set its subject's military focus to any of the following, which will determine how they behave in wars. If the subject has more than 50% liberty desire, they will always behave as though set to passive.

Focus Behaviour
No focus The subject will decide its own strategies.
Supportive The subject will seek to attach to friendly armies.
Aggressive The subject will be aggressive towards enemies, seeking battles in enemy territory.
Focus Behaviour
Passive This will make the subject stay with armies in their own territory, and defend there. Unless escaping a larger threat.
Defensive This will make the subject defend its allies' territory. (Recommended for stronger subjects)
Siege This will make the subject use its armies to siege down hostile fortresses and not seek any battles.


  1. See in /Europa Universalis IV/common/defines.lua: variables with TRIBUTE_BASE_.
  2. See in /Europa Universalis IV/common/defines.lua: DIPLOMATIC_ACTION_TRIBUTARY_ACCEPTANCE_PER_DEVELOPMENT.
  3. See in /Europa Universalis IV/common/defines.lua: DIPLOMATIC_ACTION_TRIBUTARY_EMPIRE_FACTOR.

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