Wolvesey Castle was the main residence of the rich and powerful medieval Bishops of Winchester, along with others such as the palace at nearby Bishop's Waltham.
The castle was built between 1130 and 1136 for Bishop Henry of Blois, the brother of King Stephen.
It was besieged for three weeks in 1141, during the fighting between the forces of the Empress Matilda and those still loyal to King Stephen; although accounts of the siege are confusing.
After the death of Bishop Henry in 1171, the fortifications were removed, and it became a residential palace. It remained in use until the 1680s, when Bishop George Morley (1662-84) built the current bishop's palace, which is next to the medieval site. This incorporates the chapel of the older building.
Currently (2016) admission is free, but check the official site, detailed below, which also lists opening times.