I have seen this happen two or three times already and am not sure how to explain it - a king will be ruling, say Edmund I in England. Then when I check back a little bit later, with no civil war or anything, his son will be ruling, but the previous king will still be alive, but in some other role - I've seen count, and marshal. In one case he was his son's heir! Not sure if there is a bug or if there is some unusual explanation for it, but it seems buggy.
