Son of Duncan, whom Macbeth slew, succeeded his father in 1040 as king of Cumbria and Lothian, and in 1057, on Macbeth's death, became king of all Scotland; till 1066 his reign was peaceful, but thereafter it was one long conflict with the Normans in England; raids and counter-raids succeeded each other till, in 1091, Malcolm was forced to do homage to William Rufus; next year he lost his possessions S. of the Solway, and in 1093 he was slain in battle at Alnwick; the influence of his second wife, the saintly Margaret, did much to promote the civilisation of Scotland and to bring the Scottish Church into harmony with the rest of Christendom.