A town on the Seine where Philip II of France died in 1223.
Mantes (Mantes-la-Jolie) on the Seine in northern France was a fortified town on the disputed frontier between the Capetian royal domain and the Duchy of Normandy. William the Conqueror was wounded or fell ill while sacking the town in 1087 and died at Rouen shortly after.
Mantes marks the terminal episode of William the Conqueror's reign. His burning of the town — reportedly triggered by a taunt from Philip I of France — and the injury he received there ended his active military career. The incident reflects the persistent Vexin border conflict between Norman and Capetian power that shaped French-English relations throughout the twelfth century.