The frontiers of the Roman Empire together form the largest monument of one of the world's greatest ancient states. They stretch for some 7,500 km through 20 countries which encircle the Mediterranean Sea. The remains of these frontiers have been studied by visitors and later by archaeologists for several centuries. Many of the inscriptions and sculptures, weapons, pottery and artefacts created and used by the soldiers and civilians who lived on the frontier can be seen in museums. Equally evocative of the lost might of Rome are the physical remains of the frontiers themselves. The aim of this series of books is not only to inform the interested visitor about the history of the frontiers but to act as a guidebook as well. Emperor Hadrian ordered the construction of the great Wall which still bears his name 'to separate the barbarians from the Romans' (Historia Augusta, Life of Hadrian, 11). The complex of military installations, 117 km long, but with an extension without the linear barrier for about 40 km down the west coast, contained 74 km of stone wall, 43 km of turf rampart, 200 towers, 100 fortlets, 20 forts, took years to construct and was probably still being modified when Hadrian died in July 138. This highly illustrated book offers an accessible summary of Hadrian's Wall, and an overview of the wider context of the Roman frontiers.