The Roman province of Britannia covered most of present- day England and Wales. The Romans imposed their own way of life and culture. They exerted an influence, without actually governing there, over only the southern part of Scotland. It was during this time that a Celtic tribe called the Scots migrated from Ireland to Scotland, where they became allies of the Picts (another Celtic tribe) and opponents of the Romans. This division of the Celts into those who experienced direct Roman rule (the Britons in England and Wales) and those who did not (the Gaels in Ireland and Scotland) may help to explain the development of two distinct branches of the Celtic group of languages.
The remarkable thing about the Romans is that, despite their long occupation of Britain, they left very little behind. To many other parts of Europe they bequeathed a system of law and administration and a language which developed into the modern Romance family of languages. In Britain, they left neither. Most of their villas, baths and temples, their impressive network of roads, and the cities they founded, including Londium (London), were soon destroyed, or fell into disrepair. Almost the only lasting reminder of their presence are place-names like Chester, Lancaster and Gloucester, which include variants of the Roman word castra (a military camp).