Vassals...

[Bob]

seems like they do nothing but rebel...

Had king, everyone liked. Conquer land, gave it to vassals +100 like. After he dies, they all rebel...lol wtf

[brownacs]

There are a few ways to fix that. The first's to just be super likeable. If their opinion is >80, vassals won't voluntarily stay in factions. Focus on getting beautiful + genius bred into your family, virtuous traits or +diplomacy traits won't hurt and neither will well-placed gifts when a faction's formed. The second's to focus on having relatively few vassals and maintaining alliances with them. And the third's to mix and match a bit. Having a strong army also won't hurt - especially MAA, which will be inherited - to raise the bar for a possible rebellion. I've not had a rebellion I didn't start on purpose in a long time. Alternatively, you could try to max dread, but they've made that a bit harder to get than it used to be.

[Bob]

I just wiped out their bloodline lol...

Placed army on them capital, retract fiefs. They rebel, capture, enfore demands, execute prinsoners rinse and repeat and now that troublesome house is gone >:D

[Bob]

why the fuc k, is my vassal, who's my heir....RAIDING ME towN!?!?!?!!?!?!?!!?

[endymionologist]

Originally posted by Bob:

why the fuc k, is my vassal, who's my heir....RAIDING ME towN!?!?!?!!?!?!?!!?

That's where you keep the money.

There are intended gameplay methods for dealing with this and other problems. You can Ally your son, and if he won't go for it diplomatically you can do some murder and marry him to his aunt for an automatic Alliance.
In feudal eras, sometimes a realm just *can't* be stable from generation to generation. You can still kill your way back to unity, in battle or elsewise, but it's important to set some of that up before the split with Title management and whatnot.

[Deusmodeus]

Originally posted by Bob:

why the fuc k, is my vassal, who's my heir....RAIDING ME towN!?!?!?!!?!?!?!!?

Brotherly Love.
The king is dead. long live the king.