Saint Latuin evangelized the village of Sées, at the source of the Orne, around 440 and became the city's first bishop. In the Middle Ages, Normandy had seven bishoprics and 36 regular canons. That of Sées is the only case of a merger between three towns, each run by a different entity. Under Philippe Auguste (1180-1223), the city experienced peace and built the General Hospital and the Couvent des Cordeliers. The English besieged Sées several times during the Hundred Years' War but mostly damaged the outside of the ramparts. The churches of the three towns have remained intact.