Ancient

Britain's first city
Colchester, formerly known as Camulodunum, was the first city in Britain and the capital of Roman Britain for a time
Roman Colchester was home to 3 theatres- more than any other in Britain, and hosted the only Roman chariot-racing Circus on the island. Large town houses have been uncovered with under floor heating and fine decorated mosaic floors.
Even before it was complete, the function of the fortress had been changed. The conquest of Britain had moved on and instead of a military base, what Rome needed now was a colony. The Roman word colonia was a specific term for a planned town inhabited by military veterans. They would be allocated plots of land within the bounds of the settlement in order to establish a Roman presence within the conquered area.
This is what the Roman fortress of Camulodunum was turned into. It became Britain's first-ever city. Doing this, the Romans quite literally brought civilisation to Britain, as the word derives from the Roman word civitas, meaning 'city'. The city of Colonia Victricensis (The City of Victory) was deliberately placed within the bounds of the Roman fortress, using its street plan and converting the barrack blocks into houses.
In place of the military gate at the western entrance to the fort, a monumental arch was built, commemorating the Claudian conquest of Britain. Later, when the city acquired walls, this was incorporated into the western gate of the city and though nothing of the actual arch now remains, what is left of the gate and its walls still stand at the Balkerne Gate.
Similar monuments were erected in Rome, Gaul and at Aphrodisias in Turkey. Some fragments of these survive and because the Romans used the same formula for their monuments all over the empire, it is possible to use these to reconstruct pretty accurately what this arch and gate would have looked like. The inscription will have read:
The annexe of the old fortress was converted into the precinct for a monumental Temple to the imperial cult. Today the site is occupied by a Norman castle, built directly onto the foundations of the old temple out of re-used Roman stone. However, it is possible to see what the original temple precinct must have looked like by going to Nimes, where the Maison Carée still stands, surrounded by colonnades. Once again, nothing like it had ever been seen in Britain before. Within the temple stood a life-size bronze statue of the Emperor Claudius, of which the head still survives.
The local tribal magnates were recruited into the temple cult, but the financial burden of running the temple and the arrogant maltreatment of the locals by the colonists was to cause resentment which boiled into the Boudiccan revolt.

What caused the fall of Rome? Corruption, the division of the empire, and invasion by Germanic tribes were the three main causes of the fall of Rome.