The Roman province of Britannia covered most of the present-day England and Wales. The Romans imposed their own way of life and culture, making use of the existing Celtic aristocracy to govern and encouraging this ruling class to adopt Roman dress and the Roman language (Latin). 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.
Hadrian’s Wall : - it was built by the Romans in the second century across the norther border of their province of Britannia( along nearly the same line as the present English- Scottish border) in order to protect their territory from attacks by the Scots and the Picts.