Actaully this is the one real issue I have with CK... kingdom disintigration is far too common.... so far in one game I've seen. all of these kingdoms disintigrate.... in order..
Denmark - although a german invasion has something to do with that.
Poland - no reason for this one.
England - again German agression partly to blame but since I've seen part of east england occupied by, Germany, Papal States, Fatmids, other Islamic nations,... at the point were I had English counties comming under my control by way of inheiritances I took steps and now Scotland/Lithuania now controls much of england.
Scotland - but that was by evil plots and design... my fault hehehehehehehe...
All the Spanish states- moors only took advantage of crumbling kingdoms.
France - Spectacular spontaneous combustion for no apperant reason. still a kingdom of france but it's isolated to the kings counties only.
Croatia - again can't see an apperent reason for this.
Germany - really wierd on this one.. one minute germany was united and strong.. the next it splits into 3 or 4 smaller kingdoms/duchies.
now in 1223 there are basicly only 2 contiguous contries.. Me.. Scotland/Lithuania/Russia and the Byzantine Empire... everyone else if fragmented chaos of duchies and counties... although there are some Italian duchies that are close to claiming the title King of Italy and Hungary had remained remarkable stable. and there is are two new ahistorical kingdoms of Bohemia and Burgandy that show promise.
I think the likelyhood of counties/Duchies to declare independace is too high in CK for most countries... England, France, in particular... I think the game would be much more realistic if counties did other disloyal acts other than declare independance... i.e. withhold crown contributions or taxes or such, rather than automaticly delcaring independance when loyaltly drops below 20%...
Particularly for individual counties... I've never seen so many counties going it alone... swiching alliegences I can see... but outright declaring independace should be quite unusual. like once a game occurance... rather than counties declaring independace. a more realistic senario would be for them to swich alliegance to another duke in the same country or to the crown directly. Duchies I can see declaring independance but even then only if thier vassels have alot of support for the duke rather than the king...