The county of the Vexin was a medieval French county that was later partitioned between the Vexin Français (French Vexin) and the Vexin Normand (Norman Vexin).
1074–1077 Simon, also count of Valois and Amiens, he became a monk and his properties were dispersed, Vexin being partitioned between the Duke of Normandy and the King of France