The rulers of London in the late middle ages sought to safeguard the future of their important river crossing by placing its administration in the hands of a specially created institution. By the mid-fourteenth century the "BridgeHouse", as it became known, had been endowed with a large portfolio of properties which provided the bulk of the revenue needed for the frequent, and often urgent, repairs to London Bridge's structure: as many as 130 shops stoodon the bridge itself. As well as providing information on the technicalities of bridge-building or wider issues concerning urban crafts and productive processes, the accounts and rentals from the institution's archive provide useful snapshots of the bridge at various points in its often turbulent history.