In 1362, the bridge over the Trent at Nottingham collapsed. In response, Edward III commissioned four men to inquire as to who was liable to repair the bridge ‘whereby there used to be safe transit for men and carts over the river to the said town and to the North’. The answer returned was simple: no-one was obliged to repair the bridge. It had been repaired only by alms and through the proceeds from temporary pontage tolls granted by kings over the previous half century. The king had no power to compel anyone to rebuild the bridge, so instead he attempted to prime the pump of charity once again by granting timber from Sherwood Forest. How could it be that the king had no regular manner of ensuring that a bridge of the strategic and geographical significance of the Trent Bridge be kept in decent repair? This was, after all, a site on which Edward III's forebear and namesake, Edward the Elder, had ordered a bridge to be built some four and a half centuries before.

This book is about the power of kings and the building of bridges. There has been a long tradition, from before the Romans, of associating great rulers with their great building works. This tradition was strong in the English Middle Ages: writers from Bede to William of Malmesbury, from Geoffrey of Monmouth to Ranulf Higden tell stories in which the great kings, historical and mythical, provide comfort and security for travellers with public works. This association of benevolent kings with real measures for their subjects’ safety lies behind the origins of the legal status of roads and bridges in the Middle Ages. The Anglo-Saxon kings, in seeking to provide order and security, made provision both for obligations to repair bridges and for the establishment of special jurisdiction over the highway. Both provisions were bound up with the ideology and practical constitution of the public peace in the tenth century. Bridges had many other purposes, of course: military, economic, governmental, and simply for the king's convenience in his various travels. Bridges were always of vital strategic importance – a long list could be compiled of battles fought around river crossings.