A book centring on late Anglo-Saxon and Anglo-Norman canals may come as a surprise; it is generally assumed that no such things existed. Persuasive evidence has, however, been unearthed independently by several scholars, and has stimulated this first serious study of improved waterways in England between the eleventh and fourteenth centuries. England is naturally well-endowed with a network of navigable rivers, especially the easterly systems draining into the Thames, Wash, and Humber. The central middle ages saw innovative and extensive development of this network, including the digging of...