Odd, the mongols always failed to even take one country in my games.

I have seen a game where all the byzantine duchies gained independence when the old emperor was knocked off the throne, not sure how that happened. After that the empire was reduced to thessalia.Then the old emperor took his title back and we still kept being independent. All the while the seljuks were attacking our duchies.

I usually don't have much problems keeping a unified empire in the previous patches. I will have to see that in the new patch. Just throw a grand tournament and pretty much everything is cemented again.

Historically though, the devs should have a modifier making seljuk family members hating eachother, because the seljuks had a lot of trouble keeping territories under it's banner(FM took these for themselves).

I'm up for a multiplayer game.