\paperw5085 \margr0\margl0\ATXph16380 \plain \fs20 \pard\tx3255\tx6525\tx9780\ATXts240\ATXbrdr0 \f1 \fs22 The position of the northern frontier in Roman Britain changed several t
imes during the first two centuries AD. The only way to prevent or pre-empt aggression from the north was to erect a linear barrier set with watch-towers and fortlets. To this end, during the 120s \ATXnt901 HadrianÆs Wall\ATXnt0 was built \ATXnt902 acro
ss the neck of Britain, from the Solway Firth to the River Tyne\ATXnt0 . Less than twenty years after its inception, however, it was abandoned in favour of the reoccupation of southern Scotland and the construction of a new barrier, the \ATXnt903 Antonin
e Wall\ATXnt0 . This frontier only lasted twenty years, and in 163 was abandoned. Thereafter HadrianÆs Wall was recommissioned and remained the frontier until the end of Roman Britain. By the 4th century, the principal northern enemies of Roman Britain w
ere the Picts, a coalition of tribes from the central and eastern highlands of Scotland. The Pictish kingdom, whose craftsmen produced finely carved commemorative stones, ultimately overran HadrianÆs Wall and outlived the Roman occupation.\par
