Subject nation

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File:Subject nations.jpg
The subjects interface panel, added in patch 1.4

Subject nations are semi-independent suzerainties that surrender their economic, diplomatic and/or military power to another, usually more powerful country in exchange for civil protection, courtesy of their overlord. Subject nations have, historically, been everything from de facto independent but a de jure Vassal of another country (such as the Eyalet of Egypt within the Ottoman Empire) to small states chafing under the unrestricted power of their overlords (such as the Russian Grand Duchy of Finland). All subjects have a liberty desire that determines their loyalty towards their liege.


Main article: Vassal

Vassals are the most basic and oldest form of subject nations, which give part (a base of 10%) of their monthly earnings to their overlord and have control over their own territory and military but must join any conflicts incurred by their overlord. Vassalization can occur militarily by forcing it upon a defeated enemy in a war or diplomatically through Royal Marriages and Alliances if relations are above 190. The diplomatic options of a Vassal are also limited, the likes of which are typically constrained to what best fits their overlord's interests. After a nation has been a Vassal of another country for at least ten years, their overlord can begin diplomatically assimilating them into the overlord's domain, if relations are above 190.

March icon.png March

Main article: Vassal#March

A march (introduced in patch 1.8 as part of the Art of War DLC) is a militaristic vassal that cannot be annexed, but gets significant bonuses to their armed forces:

  • +25% National manpower modifier.png National manpower modifier
  • +20% Manpower recovery speed.png Faster manpower recovery speed
  • +30% Land forcelimit.png Larger land force limits
  • +30% Naval forcelimit.png Larger naval force limits
  • +20% Fort defense.png Better fort defence
  • -15% Vassal.png Liberty desire

March status can be revoked from Vassals and turned back into a regular subjects, but will incur a -1 Icon stability.pngstability loss and -200 relations modifier with the former March.

If the total basetax of the march exceeds 60, it loses the bonuses for being a march, but it will keep the status.

Personal union.pngPersonal union

Main article: Personal union

Lesser partners in a personal union share the same ruler as that of the leading country. Like vassals, lesser 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. Personal unions can occur when a ruler dies without a legal heir, or there is an heir with a weak claim. They can be diplomatically integrated, but only after they have been the lesser subject in a personal union for fifty (50) years.

If a personal union with a nation ends upon the death of the leading nation's ruler, the former greater partner will get a "Restoration of Union" casus belli on the former lesser 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 and Hungary if Hungary's king dies without an heir.

Note: Since patch 1.8, only nations that have one of the Christian religions as their state religion are able to form personal unions, as it historically very rarely occurred outside of Europe.


A protectorate is a type of vassal introduced in patch 1.4 that can only be the subject of a greatly technologically superior nation. It acts, effectively, as a slightly more autonomous vassal that can't be annexed, but contributes economic and militaristic power to their overlord, and is a good way of controlling an area without outright annexing it.

A country can only make another country a Protectorate if the subject has a base Technology cost.pngtechnology cost at least 50% greater than the overlord's. For example, Western nations can't force an Eastern, Ottoman or Muslim country to become a protectorate, but can vassalize them; whereas they can't vassalize the rest of the world but can enforce Protectorates. Hordes are the exception to this, as they can always be vassalized, regardless of technological differences.

Changes in technology group doesn't retroactively affect the vassal-protectorate distinction. For example, if Russia (Eastern tech group) has Korea (Chinese tech group) as a vassal, Korea will remain a vassal even after Russia westernizes, even though Western nations can't normally vassalize Chinese tech group nations.

A protectorate that westernizes breaks free of its overlord as of patch 1.7.

A protectorate:

  • Cannot be diplomatically annexed.
  • Does not fill up the diplomatic relations cap.
  • Gives 50% of its Trade power.pngtrade power to its overlord.
  • Gives military access and fleet basing right to its overlord automatically, without filling up a relations slot.
  • Enjoys a -20% Technology.pngtechnology discount.
  • Has all previous Alliance.pngalliances broken, frees all vassals and cannot form new ones.
  • Can renounce its protectorate status without war, at the cost of Icon stability.pngstability, a loss of Prestige.pngprestige and a major relations hit from its overlord.
  • Can declare war against other nations (except other subjects of the same overlord) without the overlord being called in.
  • Can not be called into its overlord's wars, but automatically calls its overlord into a defensive war if attacked.
  • Cannot be the target of Coalition.pngcoalitions. One rather gamey strategy for world conquest involves a powerful Asian state deliberately becoming the protectorate of a weak Western country to avoid massive coalitions. Note: This only works in past versions of the game.

It is possible to obtain a protectorate both diplomatically and through war. A forced establishment of a protectorate is possible with 100% war score, regardless of the target nation's size, and it does not require full occupation; a sufficiently high war score (over 90%) can bring even a very large nation into Protectorate status.

Colonial nation

Main article: Colonial nation

Colonial Nations in the Conquest of Paradise DLC represent the distant New World colonial territories of European powers. They will automatically form and take control of provinces in North and South America and Australia once five fully-developed colonial provinces exist inside a single colonial region. Colonial nations can be taxed, can colonize and go to war independently, and can seek their own independence if pushed too far.

When created, their 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 company

Main article: Trade company

A trade company is a collection of overseas' provinces that provides less Income.pngincome and no Manpower.pngmanpower per month to the home country but produces significantly more Trade power.pngtrade power.

Trade companies may be formed by nations that belong to the Western tech group and own at least one province in any of the twelve trade company regions scattered throughout Africa and Asia. They differ from colonial nations in the Americas and Australia in that they are not separate governments, all territories remain part of the mother country. They are, however, listed in the subject nations panel. Provinces can be added or removed from a trade company at any time.

Client state

Main article: Client state

Client states are highly loyal, custom vassals that were introduced in Patch 1.8. They can be formed once a country reaches diplomacy tech level 22, and can be given any province or provinces that you have control over, regardless if they are cored or not. You can customize the flag and the name of a client state and can have up to ten at once. The first province that a new client state is given is automatically designated as the capital, and the Culture icon.pngculture in that province will become the primary culture of the new client state. The client state will have its creator's state religion.

Client states are usually used to core conquered land so the creator doesn't have to waste the administrative points; however, they seem to be very slow when it comes to converting said land to their religion, unless it has low basetax.

Liberty desire

All subject nations have a liberty desire between 0 and 100, indicating their wish for independence. Below 50 a state is loyal, paying taxes to its liege and taking an active part in all wars. Above 50, it becomes disloyal, refusing to pay taxes or help in wars unless its own territory is directly threatened. Disloyal states are open to accepting support for their independence from foreign nations, and may declare an independence war if they have sufficient backers. At 100 liberty desire, a state is rebellious and will declare its independence at the slightest opportunity.

Liberty desire depends on many factors:

  • The relative army size of the subject compared to its liege. There is +50 liberty desire for having 100% of the liege's forces, scaling proportionately (e.g. +25 at 50%). The combined strength of all vassals and marches is used for their liberty desire, while personal union partners, colonial subjects, protectorates and client states only consider their individual strength.
  • A base modifier depending on type of subject: -25 for marches, client states, and protectorates; +10 for Japanese daimyos; 0 for vassals, colonies and union partners.
  • +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).
  • -25 for historical friends.
  • +25 for historical rivals.
  • -3 per point of diplomatic reputation.
  • -0.25 per point of trust (min -20, max +20)
  • +10 if currently being annexed.
  • +1 per point of the overlord's war exhaustion.
  • +25 for vassals and marches with 60-99 base tax.
  • +50 for vassals and marches with 100+ base tax.
  • -50 if recently defeated in an independence war (decreasing over time).
  • +0.5 for colonies, per point of the colonial nation's administrative efficiency.
  • +1 per colonies, per point of tariff.