Roman Britain, also known as Britannia, was a province of the Roman Empire that existed from the 1st century AD to the 5th century AD. The Roman conquest of Britain began in 43 AD under Emperor Claudius, and it was largely completed in the southern half of Britain (most of England and Wales) by 87 AD. Britain was divided into two provinces: Britannia Superior, governed from London, and Britannia Inferior, governed from York (Eboracum). Emperor Diocletian later divided the province into four sepa