Forgot to mention that I'm using the Rebels and Warmongers mod.
Well I'm glad I was friends with the Mercian royal family. Especially now as my current king is a rival of the whole family of the only non-relative vassals I have. There's been a lot of, ah, accidents, in their holdings lately. In fact, looking at their family tree I see...five accidents and two executions after a father and son both tried usurping my throne, with another plot in the making. And I retract my nonrelative statement. A distant cousin has a wife in my rival family.
The Offings (my rivals) control Middlesex and Kent while my current ruler, his brothers, and one cousin control Norfolk, Suffolk, Essex, Bedford, Oxford, and Sussex, as well as a Barony in Burgos. We'd have Surrey by now if it wasn't part of a very strong Northumbrian kingdom. There are only three adult males (one I made deaf after capturing him in battle) and two girls left alive in the Offing Dynasty, so the fall of House Offing should be coming soon. We've also fought off a Norman invasion (during an aforementioned uprising) and have beaten back the Viking hordes. Up until now my Dynasty heads have been good and kind to their people, but these Offing dicks have forgotten their place. They're actually the only enemies I really have come to think of it. I've also been supporting a Viking family that's been rebelling pretty successfully and creating all sorts of issues in the Norse territories.
I do have to say a certain Telltale Games Game of Thrones may have influenced my playthrough this time around. Before I had ever played a CK game I was big into the HoI and EU games, and up until recently I didn't really get out of the "Paint the world Blue" mindset I got from those.