Wallingford provided refuge for the Empress Matilda's party during the civil war that began after her father Henry I's death. After the fall of Oxford Castle to Stephen in 1141, Matilda fled to Wallingford, according to some historic accounts in the snow under a moonlit sky. Wallingford Castle was besieged unsuccessfully a number of times, with the Treaty of Wallingford ending the conflict there in November 1153.