The end of Roman Britain and the arrival of the invading Saxons forms part of the most disruptive period in Britain's history. Centuries of relative stability as a Roman province gave way to an age of conquest and destruction. It is a period which is difficult to comprehend, coming at the end of the Roman era and in the pre-dawn of the Medieval. It is a Dark Age, both in terms of our apparent lack of source material and in our understanding of events. As a result, several legendary figures appear – it is the age of Arthur, Merlin and others; figures steeped in mystery, mysticism and magic, allowed to thrive in the paucity of the source material.

In this new analysis, Murray Dahm explores the military history of Roman Britain's slow decline, going back to the roots of the province's final rupture from Rome in the fifth century and the subsequent invasions. Using a wide array of sources, the author illuminates this dark world and examines what we know (or what we think we know) of the Angle, Jute, Saxon and other invasions that took advantage of Rome's absence and which, in their own way, shaped the Britain of today.