Hadrian's Wall (Vallum Aelium, Roman Wall, Pict's Wall, Vallum Hadriani) near Houseteads Wood - a defensive fortification in the Roman province of Britannia, begun in 122 AD in the reign of Emperor Hadrian. It stretched from the banks of the River Tyne near the North Sea in the east to the Solway Firth on the Irish Sea in the west, and formed the northern limit of the Roman Empire.