Arnulf de Montgomery

Arnulf de Montgomery
Earl of Pembroke
Arnulf's name as it appears on folio 67v of Oxford Jesus College MS 111 (the Red Book of Hergest): "ernỽlf uab roser".
Born	c.1066
Died	1118×1122
Wife	Lafracoth
Father	Roger de Montgomery
Mother	Mabel de Bellême

Arnulf de Montgomery (born c.1066; died 1118×1122) was an Anglo-Norman magnate. He was a younger son of Roger de Montgomery and Mabel de Bellême. Arnulf's father was a leading magnate in Normandy and England, and played an active part in the Anglo-Norman invasion of Wales in the late eleventh century. Following the Montgomerys' successes against the Welsh, Arnulf established himself at Pembroke, where a earth and timber castle was erected, and was probably rewarded with the title Earl of Pembroke.

At the turn of the twelfth century, Arnulf reached height, with his lordship including much of the former Welsh Kingdom of Deheubarth as well as various lands in Yorkshire. Not long after reaching this apex of his career, Arnulf assisted his eldest surviving brother, Robert de Bellême, in a rebellion against Henry I, King of England. It was also about this time that Arnulf married a daughter of Muirchertach Ua Briain, King of Munster, in what appears to have been an effort to gain military support against the English Crown. Following the ultimate collapse of the rebellion, however, the Montgomerys were outlawed and banished from the realm, and Arnulf appears to have spent much of the next twenty-odd years in a peripatetic life in Ireland and Normandy. Arnulf's career exemplifies the opportunities available to younger sons of the Anglo-Norman aristocracy. Arnulf appears to have died between 1118 and 1122. He is not known to have left any descendants, and the family's surname appears to have died with him.