The castle was erected by the Bishop of Winchester Henry of Blois between 1130 and 1140. It was the scene for the Rout of Winchester in which the Empress Matilda assaulted the Bishop Henry in 1141, during a period known as The Anarchy. The besieged defenders of Wolvesey set fire to the city, destroying most of the old town of Winchester and holding off Empress Matilda's forces until Stephen's wife, Matilda, arrived with re-enforcements from London.[citation needed]