In AD43, following the death of Cunobelinus, the pro-Roman chief of the Catuvellauni, Emperor Claudius decided to make Britain a formal part of the Roman Empire.

The Romans followed the ancient trackway up from London to the crossing of the River Lea. They created an army base at the river crossing which developed into the Roman town of Ware. The trackway became the road later known as Ermine Street, which was the main road from London up to York, via Braughing and Lincoln.