The city of Durham, although geographically far removed from the centre of political power in England in the later medieval period, was of great strategic and ecclesiastical importance during its early history. It was the seat of the prince bishops, a military headquarters for the defence of the rthern borders of England, a centre for pilgrimages to the shrine of St Cuthbert and the principal market town for the region. After tracing Durham's late tenth-century origins, the book examines the subsequent developments in religious and military building work on the peninsula which accompanied the growth of a successful urban community in the eleventh and twelfth centuries. This section of the book is complemented by the reproduction of all the extant medieval plans for Durham in an appendix, which also includes later maps of the town and several illustrations which help to explain the complex topography. Furthermore, although at first sight Durham's overlords might seem oppressive, there is little evidence of the townsmen's dissatisfaction with their rule, and ne of urban revolt in late medieval Durham.