I am playing with the Byzantines, and I was planing to take Naples and Sicily owned by Sicilians. I had no provinces next to them and their navy was stronger than mine. So I decided to send assassins.
Their king, Angus I had only one son (Alexander) and two brothers (Adam and Aed). So I sent about 10 assassins (ranks 1,2,3). One of them assassinated Angus. After that Alexander became king (Alexander I, age 17), and Adam and Aed ex-princes. Ok, that's what I planed. Then I eliminated Alexander as well and thought Sicillians will disappear as faction. But I noticed they have a new king Aodh I, age 39. So, from where did he come from??