Macbeth (măkbĕth´), d. 1057, king of Scotland (1040–57). He succeeded his father as governor of the province of Moray c.1031 and was a military commander for Duncan I. In 1040 he killed Duncan in battle and seized the throne. Possibly of royal descent himself, he acquired a direct claim to the throne through his wife, Gruoch; she was a granddaughter of Kenneth III, who had been overthrown by Duncan's ancestor Malcolm II. Macbeth represented northern elements in the population who were opposed to the ties with the Saxons advocated by Duncan. Macbeth was defeated in 1054 by Siward, earl of Northumbria, who regained the southern part of Scotland on behalf of Malcolm Canmore, Duncan's son. Malcolm himself regained the rest of the kingdom after defeating and killing Macbeth in the battle of Lumphanan. He then succeeded to the throne as Malcolm III. William Shakespeare's version of the story comes from the accounts of Raphael Holinshed and Hector Boece.