Kenneth II was the king of Scotland in succession to Cuilean. He was the son of Malcolm I, and younger brother of Dubh, who had ruled before Cuilean. He was a contemporary of the English king Edgar, by whom he was acknowledged as King over Lothian (which he had seized), in 974CE. Later, in 994, he invaded England, was defeated, lost Lothian and was challenged by Cuilean's son Constantine, who killed him in 995 and was elected king in his place, under tanistry.
Kenneth came to the throne in 971, and must have married, to have had a son Malcolm who was, in his turn, to take the throne. As well as wars with England he was also in conflict with Sigurd of Norway over the lands in the north of Scotland, by the Orkneys.
Much of his life, and his period of rule is a mystery -- date of birth, identity of his wife (said, in one unsupported source [Berchan's Prophecy] to have been a princess of Leinster), other children. He is supposed to have killed Cuilean's brother Olaf shortly after coming to the throne, probably to prevent him becoming a rival for the kingship, and this is reportedly the reason Constantine killed him 20 years later. But an alternative story says he killed a mormaer's son, and the grieving mother built a crossbow trap, triggered by a golden apple, and induced him to take the apple from where it was, in a statue's hand.