Bad Christian vassals :p

[Marshall18]

I was playing as England, had formed Britania and conquered the Kingdom of Sicily.The pope called a Crusade for Jerusalem, so I sent 90% of my army (including my king). As soon as I arrived, half my vassals started revolting because of a plot of some duke to get independence.
How am I supposed to be willing to go on Crusades if my vassals use the chance to back-stab me?
Any one experienced this kind of stuff, and what could i do?

Thanks

 

[Revshawn]

For the most part, once I form a large Empire like that I would make sure that I don't wage war too far from my lands if a rebellion has grown that strong, especially if I have a bad King or Emperor with many negative traits that give the vassals the sadface on account of positive/negative relations. My advice to you would be to raise the troops of said dukes that are under rebellion watch and go into the crusade with half of your force hidden behind your back. That way if the Dukes rebel, their troops will auto-disband back to base and you can raise your loyalists to fight the rebellion. Put them down quick enough and there will still be enough party in the Crusade for you to go crash it.