THE Fenland, that stretch of marshy land which covers some 1300 square miles of the eastern counties, has played a greater part than might have been expected in the history of Britain. It is just possible that there was some settlement in prehistoric times, seeing that Guthlac himself chose what may have been a prehistoric chamber grave as his abode. It is more probable, however, that this was a Roman rather than a prehistoric barrow, for a chambered grave in this area dating from prehistoric times would be a very surprising exception to the general pattern of distribution of these monuments. During the Romano-British period, as recent research has shown, parts of the Fens were comparatively densely settled. The irregularly shaped and small rectangular fields associated with the Celtic system of agriculture are found in various places throughout the area and would seem to suggest a fairly widespread occupation until somewhere about the middle of the fifth century. But by the end of the seventh century, when the Anglo-Saxon invaders had already been in the country for over two hundred years, they were thought of as typical marchlands such as the place where Grendel dwelt. He dwelt in the ‘borderland, the fens and the fastnesses’, and in the ‘misty marshes’ in ‘perpetual darkness’. Felix describes Guthlac's place of retreat in similar terms (c.xxiv). But whether there were any survivors of the British race is a more difficult question.