The Celts burnt the relatively new Roman town to the ground, and archaeological digs have revealed a layer of red ash beneath the City of London, which is believed to be the burnt remains of the old Roman town.
After the fall of the Roman Empire, Londinium was abandoned and a Saxon town named Lundenwic was established approximately one mile to the west in what is now Aldwych, in the 7th century.
Westminster was once a distinct town, and has been the seat of the English royal court and government since the mediƦval era.
This is where London began as a Roman colonial town around AD 50, at the point where the Romans built the first bridge in London.
Known as Londinium, the town was located at the northern end of the bridge the Romans had built across the Thames, on a route to their provincial capital at Colchester in eastern England.
Other elements of the urban fabric were a forum, a temple complex, a governor's palace, a wharf along the river for landing, a large fort (portions of which can still be seen at the Barbican Centre), and a great wall, built about AD 200, which roughly enclosed the area that later became the City.