ANTONINE WALL

Roman frontier barrier in Britain, extending about 36 1/2 miles (58.5 kilometres) across Scotland between the Clyde River and the Firth of Forth. Ordered by the Roman emperor Antoninus Pius, the wall was built in AD 142 by Lollius Urbicus, governor of Britain. The wall was 14 to 16 feet (4 1/2 metres) wide and probably 10 feet (3 metres) high; a ditch 40 feet (12 metres) wide and 12 feet (4 metres) deep ran in front of the wall, and a military road ran behind it. A series of 19 forts, separated by intervals of 2 miles (3 kilometres), controlled the wall. Construction of the wall extended the northern boundary of Roman Britain farther into Scotland and provided defense beyond Hadrian's Wall, which had been completed some 100 miles (160 kilometres) to the south in about 136. Occupation of the Antonine Wall was interrupted during the northern revolt (AD 155158), and the garrison withdrew to Hadrian's Wall not later than the year 196. Traces of the wall still remain.