The historical King Arthur seems to have been a petty British King, a commander of allied cavalry, whom the Romans left to his fate when their regular infantry were withdrawn from the garrison towns of Britain at the beginning of the fifth century. If a Procopius had been his chronicler, the ogres and fairy ships and magicians and questing beasts would not have figured in the story except perhaps as a digressive account of contemporary British legend. Instead we should have a lucid chapter or two of late Roman military history – Arthur's gallant attempt to preserve a remanant of Christian civilization in the West country against the pressure of heathen invasion. And Arthur's horse would have been a big-boned cavalry charger, not a fairy steed flying him wildly off towards the Christian millennium.
- Robert Graves, Foreword to Count Belisarius (1938)