William de Valence, 1st Earl of Pembroke

Who was William de Valence, 1st Earl of Pembroke?

William de Valence, born Guillaume de Lusignan or de Valence, was a French nobleman and Knight, who became important in English politics due to his relationship to Henry III. He was heavily involved in the Second Barons' War, supporting the King and Prince Edward against the rebels led by Simon de Montfort. He took the name de Valence.

He was the fourth son of Isabella of Angoulême, widow of king John of England, and her second husband, Hugh X of Lusignan, Count of La Marche, and was thus a half-brother to Henry III of England, and uncle to Edward I. William was born at Valence, near Lusignan, sometime in the mid-to-late 1220s.