This thesis aims to examine the size and scale of Germanic piracy in Roman Britain. It includes criticism of the central arguments in scholarly work on the subject. The poverty of conclusive evidence for the naval activity of Germanic tribes has inevitably led scholarly opinion to differ quite clearly in vital areas of interpretation. In the thesis I identify the most diffuse areas of Romano-British history, juxtapose contrasting scholarly views, re-examine the arguments provided by these scholars, and raise questions and suggest alternative interpretations based on the available evidence. The main topics include the development of Germanic social-, military- and technological capacity for piracy, the accumulation of portable wealth in British settlements potentially exposed to piracy, and the nature of the chain of Roman coastal installations in Britain called the ‘Saxon Shore forts’.