Stop vassals warring outside realm?

[skunkpuppy]

Hi guys,

I am a clean border freak. I hate it when my vassals expand their lands outside their de jure borders. When they are my direct vassals I can try to forge claims on the extra bits and revoke them, but if they are my vassals' vassals, I can't do very much. Is there any way to stop them? I'm using all the DLCs.

 

[PK_AZ]

Set Conclave off and get absolute crown authority as soon as possible. It doesnt resolve all problems, but you probably be satisfied.

 

[Naughtius Maximus]

Get Imperial Administration, activate viceroyalties, start formenting factions, revoke the traitors, keep their top title (king) to piss off their subordinates, get into another civil war, revoke traitors again. Rinse and repeat until everyone is under viceroyalties. This keeps everything de jure as unless they personally own the land, the new duke/king only gets the de jure territories.

Note: May take 100 years worth of civil wars, so make sure there's no outside influences like Mongols knocking at your door.

 

[balmung60]

Or if you want to get your hands dirty with some modding, I'm pretty sure you can still mod the "no internal vassal wars" and "no vassal wars, period" effects back in.