What does the history of the financing of bridges tell us about the history of the English Middle Ages? The seven centuries from c. 700 to c. 1400 can be divided into four shorter periods.

The period between c. 700 and 871 is obviously the most difficult about which to say anything definite. The obligation to build bridges first appeared in the charters, not as a vital part of governance, but as a symbolic borrowing from Roman and Continental law. There were few bridges and the duty was not important. The archaeological and environmental evidence suggests that most rivers could be forded without difficulty.

The period from 871 to 975 marks a great period of transformation in the law of bridges as it does in so much of English history. The heyday of the West Saxon dynasty stands out as a period of innovative governance and distinct royal ideology. It is in this context that the narrative sources reveal that Alfred the Great, in turning the tide against the Vikings, insisted on the fulfillment of the common burdens, including bridge-work. At the same time, the evidence of charters and the bounds attached to them suggests that bridges were indeed becoming more common. Alfred's insistence was in part connected to the conduct of the war: in the war of movement that the Anglo-Saxons were fighting, the ability to secure the major river crossings was crucial. There was more to it, however. At the root of Alfred's success was the achievement of consensus among his followers in fighting the invaders; his descendants took advantage of this surprising period of domestic peace to build a public order. The pattern of the obligations established by Alfred and his descendants indicates that bridge-work was a fundamental part of this order. The law codes of Æthelstan and Edmund show this order being considered, agreed and put into action. The charters of the same period show bridge-work being regularized at the same time, evolving from a war-time necessity to a peace-time duty. And, indeed, archaeology and place-name evidence suggest that as economic development transformed the environment so bridges were a necessary part of a new, more settled landscape. The evolution of the law of bridges in this period demonstrates practical aspects of the ideology of kingship.