How to take over a throne at the same time keep the allies of the previous king despite cultural/religious differences
Like when Alexander the Great died, several regions were ruled by his generals. In a similar case, when one of the regions
(Region A) overthrow the general and with support of another kingdom.
(Region B) take over the Throne.
(Region C) how the power can be secured if the supporters of region C have a grudge with them.
(Region A and B) because lost the war/different religion etc?
1) They have no other choice as they are clearly outnumbered (bigger army diplomacy)
2) They don't want a civil war.
3) New king is generous and gives more land to the houses, confiscated from the ones who died at war in exchange for support.
Problem is, if the grudge is strong, nothing of that would justify them putting a smile on their face for years to come LOL unless... magic. But I'm thinking of a non-magic way.
To add more context like alternate history. If a a kingdom similar to Rome, who govern several places each can have their God, as long as pay taxes. Let's say a revolt happens, in a similar fashion as Jewish revolt against romans. However imagine they actually got support from an important kingdom rivals of the romans. Now they are armed and outnumber the romans. So we have an empire where the kingdom is assaulted, the king "of Rome" is dead. However, to avoid civil war they have to make terms with the houses defeated who supported the killed king. The guy in charge of the revolt could be a man like Saladin who conquered Jerusalem but did not butcher and slaved everyone (per the movie Kingdom of heaven). If there are difference beliefs of religion. The houses of the conquered kingdom will never open heartedly embraces the religion (or way of life) of the conquerors. However something prevents a civil war.