During a wide-ranging conversation, the historian contemplates his new study of Late Roman Britain and early Anglo-Saxon England and recent evidence and perspectives found in the period that sits uneasily between the two.

First of all, Nicholas, congratulations on the publication of this endlessly fascinating and absorbing work. In the introduction, you describe the book as a fresh look at the subject rather than a rehash of your earlier work, Rome, Britain and the Anglo-Saxons, some...