These walls were named for two Roman emperors, Hadrian and Antoninus Pius, and are the most famous Roman walls. The walls discouraged raids and revolts. But their main purpose was to remind the tribes on both sides that the Romans were masters. The walls also made it easier for the Romans to control trade and to collect taxes. Hadrian's Wall was built in the A.D. 120's.
Parts still stand.
For half its length, it was all stone. The rest was stone and turf. The Antonine Wall was built in the A.D. 140's, north of Hadrian's Wall. The Romans allowed Hadrian's Wall to decay until 211, when they could no longer defend the Antonine Wall. Then they rebuilt Hadrian's Wall carefully.