Jonn

Celestial Emperor during the late third century of the New Empire.
Jonn had been King of Brugund before winning enough support from the other kingdoms to be accepted as Emperor.
Jonn's rule as Emperor was disastrous. He was unable to exercise any real power from the centre, and could not prevent the outbreak of several inter-state wars. His attempts to raise taxes were extremely unpopular and ultimately unsuccessful. He was denounced for his sinful ways (he kept many mistresses and fathered many illegitimate children) by the Church.
Shortly before his death, Jonn attempted to replace the rules of Grand Conclave and name his favourite illegitimate son, Willum Helltongue, as his successor. This was too much for the nobles of the Empire. Immediately after Jonn's death, they arrested Willum and hanged him. Holy knights acting on the orders of the Patriarch himself hunted down Jonn's other illegitimate children and similarly executed them.
Then the most powerful nobles of the Empire gathered to call a Grand Conclave to select the new emperor as usual.