The increase in urban archaeological work during the last twenty years has both illuminated many facets of pre-Norman life and demonstrated the development of individual sites to an extent hardly conceivable before. Nevertheless, the only well-defined group of sites to have received concentrated attention has been the burhs of Wessex. Prompted by Biddle's work at Winchester and Hill's elucidation of the Burghal Hidage, the establishment of a network of fortified centres and its development into an urban hierarchy in which the component sites variously played commercial, industrial, administrative and ecclesiastical roles has been charted in some detail. Beyond the frontiers of Wessex, Atkin has drawn together the available data from East Anglia. Rahtz has briefly presented the excavated evidence from the towns of the West Midlands, ‘English Mercia’; within the area of Mercia that was to become the south-eastern Danelaw (Bedfordshire, Cambridgeshire, Huntingdonshire and Northamptonshire), Williams has surveyed the new evidence for the urban development of Northampton, the best understood centre in the region, while Haslam has suggested that Bedford and Cambridge are examples of a group of sites, numbering a dozen or more and spread across pre-Viking Mercia, where urban origins can be traced back to deliberate foundation by Offa. North of the Humber, York has a singular position; it is the only important Northumbrian urban centre mentioned in late Anglo-Saxon historical sources, and seems to have achieved a sustained regional preeminence greater even than that of Winchester in Wessex. It has recently been reviewed; there is also a recent study of London.