1911 Encyclopædia Britannica/Mowbray, Robert

MOWBRAY, ROBERT (d. 1125), a Norman who was appointed earl of Northumberland between 1080 and 1082. In 1088 he and his uncle Geoffrey, bishop of Coutances, sided with Robert, duke of Normandy, against William Rufus, but they were pardoned at the close of the rebellion. In 1091 Mowbray defeated Malcolm Canmore of Scotland, who had invaded England, and in 1093 surprised and slew this king near Alnwick; soon after this event he succeeded to his uncle’s vast estates. In 1095 he led a rebellion which had for its object the transference of the crown from the sons of the Conqueror to Stephen of Aumale. Rufus marched against the earl in person, and Mowbray shut himself up in Bamborough Castle, but he was captured by treachery, escaped, and was captured again. He was then deprived of his possessions and kept a prisoner for the rest of his life, nearly thirty years.

See E. A. Freeman, William Rufus, especially Appendices C. C. F. F. (Oxford, 1882).