Written from a post-colonial North American perspective, this study considers the ways in which medieval British writers, in the wake of the Norman Conquest, used Arthurian historiography to reflect their fears about `colonial contamination' and about borders in general. The first half of the study examines the presentation of British history in works written on the Anglo-Welsh border. Warren then examines literature from the continent to look at British history from a Norman perspective. Parts of this study have been previously published.