Age of Civilizations Wiki

Unions are a mechanic in Age of History 2 that allows two countries to simultaneously unite into one country. They are accessed through the Diplomatic Actions menu.

How to form a Union[]

While there is not a set-in-stone method of reliably creating a Union, there are some methods that can nail a player close to meeting the criteria for one. As follows, it is recommended to:

  • Be in an alliance with the nation you are attempting to unite with.
  • Have a high enough diplomatic score (usually +60 or above will do).
    • If a player is having trouble accomplishing this, joining into wars started by a CPU civilization or bringing an allied CPU civilization into a war with one nation will usually boost diplomatic score up.
  • Have patience. Repeatedly spamming the "Form Union" button will get you nowhere close; in fact it may dissuade a civilization from trying to form one with you.

Pre-determined unions[]

When a player forms a civilization, normally, Age of History 2 will combine the flags of the two nations into one, as well as changing the name of the nation who asked for the union to where it has both countries' names (for example, China-India). However, in some occasions, that will not happen, instead, the game will of course combine the land of the two nations, however the game instead changes the country of the player to be that of an already existing country. This is a pre-determined union.

Pre-determined unions are easy to spot; this is evident with Poland-Lithuania, as the flag will not be a combination of two.

List of Pre-Determined Unions[]

Union Country Country Country Country
Austria-Hungary Austria Hungary None None
Polish-Lithuanian Empire Poland Lithuania None None
Kalmar Union Denmark Sweden Norway None
Czechoslovakia Czech Republic Slovakia None None
Iberian Union Spain Portugal None None
Australia-Hungary Australia Hungary None None
United Kingdoms Sweden Norway None None
United Kingdom Scotland England None None
Korean Empire North Korea South Korea None None
Yugoslavia Serbia Bosnia and Herzegovina Croatia Montenegro
Germany Germany Federal Republic of Germany Germany None
Peru-Bolivian Confederation Bolivia Peru None None
Three Empires Great Britain Spanish Empire France None
Great Britain England Scotland None None
Baltic Empire Polish-Lithuanian Commonwealth Sweden Russia None
Polish Swedish Union Poland Sweden None None
British Swedish Empire Sweden Great Britain None None


  • Only 2 unions do not include any European nation.
  • The game does not treat unions as being a new country, so by changing government type, it is possible to revert back to what your original country was before-hand.
    • For example, if Circassia and another nation were to unite, then Circassia changed its government type, the game would remove the illusion of being in a union, and Circassia would go back to being Circassia.