Since archaeology is an ongoing process, archaeological discoveries must repeatedly be reassessed in terms of a constantly developing historical context. This study attempts to do that, and, particularly, to reconcile the up-to-date archaeological record with existing documentary sources. The Prologue shows how traditional and contemporary approaches to the study of Roman military history in Britain have shaped accounts of the Flavian period (AD 69-96). It summarises fact and fiction regarding the achievements of Agricola's seven-year governorship (AD 77-83), and demonstrates how recent discoveries are now beginning to present a new picture of first-century campaigning in northern Britain. It also introduces the documentary sources, especially the place-names and tribal areas on 'Ptolemy's Map', the place-names in the British section of the Ravenna Cosmography, and the text of Tacitus' Life of Agricola, which are used to examine the military zone (north of a line roughly from Bristol to Lincoln). Part I deals with the political and geographical structure of Britain - as far as possible from the native standpoint. Chapter 2 presents and discusses identifications for each place-name in the Ravenna list and advocates an accurate, 'regional' distribution of names. Chapter 3 builds upon this, by using the place-names, together with the information from Ptolemy's map and other classical sources, to determine the tribal areas, which are vital for understanding the situation that the Romans encountered. Part II superimposes the historical narrative; it shows how Tacitus' account does indeed fit well with the geopolitical infrastructure of Britain, highlights the remarkably close correspondence between documentary sources and archaeological discoveries, and produces a greatly enhanced understanding of the Roman campaigns within northern Britain during the first century. However, the original Ravenna document was compiled no earlier than the second century, because it includes place-names associated with both Hadrian's Wall and the Antonine Wall. The Epilogue looks at the dating issue, suggests a date c.142-3, and shows how the place-names can be used to explain the reasons behind the reorganisation of northern Britain and the renewed advance into Scotland as far as the Tay, which took place in the early years of the reign of Antoninus Pius (AD 138-61).