King John's treatment of William is the most notorious example of his capricious approach towards his subjects. William, a major Welsh marcher lord, supported John's claim to the throne in 1199. But his capture of John's nephew and dynastic rival Arthur of Brittany, at Mirebeau in 1201, proved his downfall, for he was one of the few who knew that Arthur had been murdered. John became increasingly concerned about his loyalty. From 1205, he determined to destroy him after Matilda, William's wife, blabbed something about Arthur's fate. John ruthlessly hounded the family. Matilda and her sons disappeared, and William died in exile in France in 1211.
Subjects: British History — European History.