Under Saxon rule, Alfred the Great rebuilt Winchester and its defences as part of the burh system developed to protect against Norse incursions. Winchester was later chosen as the location of one of the first Norman castles in England, with Winchester Castle being built alongside the walls in 1067. As well as the royal castle in the West of the city, Wolvesey Castle, the palace of the Bishop of Winchester, was built in the East of the City alongside the River Itchen; during the Civil War known as The Anarchy, the forces of Queen Matilda, on behalf of King Stephen, besieged the forces of Empress Matilda, destroying much of the old city including the urban defences, in an event known as the Rout of Winchester.