THe castle was founed in the aftermath of the Norman conquest of England when William the Conqueror (1066–1087) ordered its construction because he wished to have a fortified place in the town of Norwich. It proved to be one of his two castles in East Anglia, the other being Wisbech.[1] In 1894 the Norwich Museum moved to Norwich Castle and it has been a museum ever since. The museum & art gallery holds significant objects from the region, especially works of art, archaeological finds and natural history specimens.

The castle is one of the city's Norwich 12 heritage sites.

Norwich Castle was founded by William the Conqueror some time between 1066 and 1075. It originally took the form of a motte and bailey. Early in 1067, William the Conqueror embarked on a campaign to subjugate East Anglia, and according to military historian R. Allen Brown it was probably around this time that the castle was founded. It was first recorded in 1075, when Ralph de Gael, Earl of Norfolk, rebelled against William the Conqueror and Norwich was held by his men. A siege was undertaken, but ended when the garrison secured promises that they would not be harmed.

Norwich is one of 48 castles mentioned in the Domesday Survey of 1086. Building a castle in a pre-existing settlement necessitated the destruction of existing properties. At Norwich, estimates vary that between 17 and 113 houses occupied the site of the castle. Excavations in the late 1970s discovered that the castle bailey was built over a Saxon cemetery. The historian Robert Liddiard remarks that "to glance at the urban landscape of Norwich, Durham or Lincoln is to be forcibly reminded of the impact of the Norman invasion". Until the construction of Orford Castle in the mid-12th century under Henry II, Norwich was the only major royal castle in East Anglia.

For more information visit the website - https://en.wikipedia.org/wiki/Norwich_Castle