Norwich Castle is a motte and bailey medieval royal fortification founded by William the Conqueror some time between 1066 and 1075. Norwich is one of 48 castles mentioned in the Domesday Survey of 1086.
The stone keep was probably built between 1095 and 1110 and it still stands today, although its outer shell has been repaired repeatedly, most recently in 1835–9 by Anthony Salvin, with James Watson using Bath stone. It’s 95 ft (29 m) by 90 ft (27 m) and 70 ft (21 m) high, and it’s of a hall-keep type, entered at first floor level through an external structure called the Bigod Tower.
In Lent 1190, violence against Jews erupted in East Anglia and spread to Norwich. Some people fled to the safety of the castle, but those who did not were killed in their hundreds. From 1200, the castle was used as a prison for felons and debtors, with additional buildings constructed on the top of the motte next to the keep.
The castle is open today as a museum and art gallery.