A large and important town grew up around the fortress over the following 150 years. It centred on the south-west bank of the River Ouse. The Romans called it Eboracum.

By the early third century a visitor to Eboracum would have seen a town and fortress surrounded by strong stone walls. The walls were symbols of Eboracum and Rome's importance as well as defences.

One of the most important parts of these defences - the Multangular Tower - is still here today.

Eboracum remained a very important settlement in the north of England. Constantine was declared emperor there in AD306. However, during the fourth century, the fortress and town started to change in character and level of occupation. How this affected the defences is not clear.

What is clear, however, is that the line of the defences established during the period from 71 to around 400 was to have a lasting effect on how York developed down to the present day.