From BiblePortal Wikipedia

The Nuttall Encyclopedia [1]

A thane of the north of Scotland who, by assassination of King Duncan, became king; reigned 17 years, but his right was disputed by Malcolm, Duncan's son, and he was defeated by him and fell at Lumphanan, December 5,1056.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

a Scotch prelate, was probably bishop of Ross about 1126. He died in 1128. See Keith, Scottish Bishops, page 184.