In the period A.D. 400-1100, perhaps more than in any other, it is necessary to bring together the results of historical, archaeological and place-name studies. Each provides information that is either badly preserved or not preserved at all in the other two, but it is not always realised how great are the difficulties involves in co-ordination and integration. This book, originally published in 1962, draws attention to the problems and provides a basis for discussion.