An independent realm in Crusader Kings II is the highest judicial structure a character is part of.
Every realm is ruled by one independent ruler, who under them has a number of vassals. They are typically the most powerful character within the realm.
- If anyone outside the realm has a Casus Belli upon any character within the realm, (s)he has to declare war upon this independent ruler.
- On the other hand, depending on the realm laws, characters within it can declare war upon independent rulers outside the realm, and the rest of the attacker's realm will not be involved.
A sub-realm refers to all titles a character holds, and the vassals below them. A Duke within a Kingdom, for example, is the ruler of a sub-realm consisting of his Duchy and all his vassals.
Realm size is the total number of settlements (castles, cities, temples, and tribes) in a realm. It is useful for estimating a character's approximate power; the larger the realm, the more powerful they generally are. However, buildings can change this power-balance a lot.
Your realm size is shown at the top right corner of the screen. You can see the realm size of other rulers by hovering their demesne size box (above their wealth, prestige, and piety). The "Realm Tree" view also shows realm sizes for all rulers in an independent realm.
Some minor titles are linked to the realm and the relatives of the ruler. Unlike honorary titles, these titles are granted automatically and cannot be revoked:
|Title||Dignity||Monthly salary||Monthly prestige||Notes|
|Regent||0.9||0.10||0.02||In case of regency of the realm. Not shown in character's title.|
|Ruler Consort||0.88||0.10||0.02||Uses the other gender version of the ruler's title.|
|Tanist||0.86||0.07||0.02||Realm heir, in case of Tanistry succession law.|
|Queen Mother||0.85||0.05||0.01||The mother of a King-tier or Emperor-tier ruler.
|Prince/Princess||0.80||0.05||0.01||Children of a King-tier or Emperor-tier ruler.
|Concubine||0.05||0.02||0.01||Concubinage marriage mechanic. Not shown in character's title.|