The Antonine Wall lay at the very extremity of the Roman world. For a generation, in the middle of the second century AD, it was the north-west frontier of the Roman empire. Furthermore, it was one of only three "artificial" frontiers along the European boundaries of the empire: the other two are Hadrian's Wall and the German Limes. Although the Antonine Wall fits into the general pattern of Roman frontiers, in many ways it was the most developed...