Domesday Book England map
Map of England at the time of the Domesday Book

There were only 18 towns of over 2,000 inhabitants in the Domesday England of 1086. Of these towns, the two largest, London and Winchester, were left out of the Domesday Book entirely.

The population of the entire country was probably between 1.2 and 1.5 million, most of them in the south and east, as you can plainly see by the distribution of major towns.

It is interesting that several of the Domesday towns, like Oxford and York, continued to grow during the medieval period, while others like Wallingford, Thetford, and Dunwich became quiet backwaters.

More:
William the Conqueror
Glossary of terms used in the Domesday Book