Bridges were not built in numbers until the 10th to 11th centuries:
"The conclusion to be drawn from the charter bounds, place-names and narrative evidence is that there were few bridges in England before the tenth century, and that the great period of the building of bridges at points previously unbridged was between 900 and 1200."Among the reasons for increased bridge-building were environmental changes, with faster runoff and banking making fords less usable, and a move from pack animals to horse carts.
So why do bridgework obligations appear in earlier Anglo-Saxon charters? Cooper looks in detail at Boniface and the 749 Gumley Charter and argues that these obligations were "not a vital part of governance, but a symbolic borrowing from Roman and Continental law".
Cooper surveys debates about the purpose of bridge-work, its links with military service and fortification, and the existence of county-wide bridge-work obligations, looking at six unusual early bridges. Bridge-building and the imposition of bridgework obligations were part of West Saxon state-building and public order.
After 975, and especially after the Norman Conquest, the notion of a universal bridge-work obligation "beyond even the remittance of kings" rapidly decayed.
"William and his sons remitted bridge-work as a mark of favour. ... Once they had chosen to excuse their most favoured monastic institutions from communal public duties, the way was open for every house of any standing to excuse itself from these obligations by forgery."
How then were bridges maintained in the 13th and 14th centuries? Though not universal, obligations persisted, some tied to particular estates, some to broader territories. Court cases reveal a complex network of attempts to impose or escape obligations, through legal pretexts and the creation of historical stories.
Turning to charity and charitable trusts, Cooper first corrects some common misunderstandings about London Bridge:
"the stone bridge at London was completed on the initiative of the king, who drew from the knowledge he had gained in his French possessions, using a French builder who employed French building techniques and introducing a French method of financing the bridge."He looks at other examples of bridge charities and at royally-endorsed alms collectors who offered indulgences in return for donations, often in areas far from the bridges concerned.
The third approach to funding bridge maintenance was through royal grants of pontage, tolls on goods for sale. These were related to grants of pavage, for paving towns, and to laws about "the king's highway". Bridge maintenance differed from road maintenance, but in medieval England both depended on the power of kings.
Bridges, Law and Power is a monograph on a relatively narrow topic, but its more arcane material is relegated to footnotes, which average around a quarter of each page. No background in law is assumed, nor any in-depth knowledge of the period. For the non-specialist it offers a different perspective on medieval state-building and the development of English law, with some intriguing details.
Note: Those more interested in bridge engineering and architecture should look at David Harrison's The Bridges of Medieval England.