Hadrian's Wall ( or ) is a stone and turf fortification built across northern Great Britain by the Roman Empire in the early second century. The Roman emperor Hadrian built the wall to control barbarians: the ancient Britons to the north of the wall. The wall is now in England, and runs between the Solway Firth and the River Tyne in northern England. When the Romans built the wall, it was the northern border of the Roman Empire. 