Dubh ("Duf" or black in English) was the son of Malcolm I. He succeeded Indulf on the Scottish throne, but faced a challenge from the son of his predecessor, Culen, who challenged him twice, and killed him on the second occasion, in 962CE.
Shortly after, he was taken ill and, believing him on his deathbed, lawless men rampaged stealing and robbing. Dubh, however, recovered and scoured Moray and Ross, finding and executing the ringleaders. In typical style, the relatives of the executed men decided to seek revenge, and in 966 or 967 they ambushed the king at the castle of Forres, and arranged for his assassination, hiding his body in a stream-bed. The body, being discovered, the guilty men were themselves put to death, and Dubh was buried in Iona.
He was married, and of his sons one became king of Scotland (Kenneth III]) and the other king or underking of Strathclyde (Malcolm).