William stayed in York in Christmas 1069 and it must have been a depressing place. Most great buildings of the Viking age were gone or in ruins. The lively, prosperous capital of the north had been wrecked.
The reconstruction of military buildings began almost immediately. The two rebuilt castles towered over the surviving low houses and the ruined Minster, an unmistakable symbol of the power of the new king.
The city’s defences were reinforced in a more unusual way. Near to the larger castle, at Clifford’s Tower, a dam was constructed blocking the Foss. The resulting reservoir became known as the King’s Fishpool, which provided an impenetrable barrier to the east of the city. This is why there is no wall to that side.
Civilian York took a longer to recover - of the 1,400 or so houses recorded in the Domesday Book of 1086, more than half were deserted and derelict.
However the defences weren’t the only interest of the city’s Norman rulers, they also embarked on a massive campaign of church building.