A bridge was built across the River Nene around AD 65, after which a small settlement grew to the south west of the bridge. This prospered as a market centre for trade along the important Ermine Street, the precursor to the modern A1. The town had walls around it for protection and status, and developed major public buildings where a town council met and organised local government, which had controls over roads, cemeteries, baths, water supply and all aspects of the daily life of the town. Added to the towns market importance was its rich sources of clay and iron which were the key resources of a major pottery and metal working industry. The importance of Durobrivae lies in the fact that although the town walls covered 44 acres, the industrial suburbs extended for another 450 acres making a major settlement in Roman Britain.
The area to the south of Ailsworth and Castor villages is known as Normangate Field. It was the site of extensive Roman pottery and metal working workshops. The Roman road of Ermine Street runs through the area. It can be seen today as a massive bank of earth concealed underneath several hundred years of repeated road surfacing. The potteries here gave their name to the distinctive Roman pottery known at Castor Ware. Interpretation from 2018 has revealed that the Normangate Fields contained a complex and thriving community. The location of the fields put the pottery and metal workers in an excellent position. They were near the Praetorium, Durobrivae and Rive Nene for water-based transport. Also, not only were they straddling Ermine Street, but King Street too. It is possible that King Street was once much more important than Ermine Street based on the location of the workers.
