Maol Chalvim I
He was the father of Duff, Kenneth II, and Prince Malcolm by three successive wives, the last one, Malcolm's mother, being Queen Katharine (Duff's and Kenneth's mothers had died in childbirth). When he died in 954, he asked his older two sons to look after his widow Katharine, which they promised to do; the ambitious lord Indulf would exploit this promise when he seized the Scottish throne afterwards.
Maol Chalvim I was buried at Iona.
Real World Background
Maol Chalvim was a real Scottish king, better known as Malcolm I. In actual history, he was slain in battle against the men of Moray at Fetteresso in 954. He was indeed the father of Duff and Kenneth, although Prince Malcolm is a fictional character.