The site

The site

The abutments of modern London Bridge rest several metres above natural embankments of gravel, sand and clay. From the late Neolithic era the southern embankment formed a natural causeway above the surrounding swamp and marsh of the river's estuary; the northern ascended to higher ground at the present site of Cornhill. Between the embankments, the River Thames could have been crossed by ford when the tide was low, or ferry when it was high. Both embankments, particularly the northern, would have offered stable beachheads for boat traffic up and downstream – the Thames and its estuary were a major inland and Continental trade route from at least the 9th century BC.^[4] There is archaeological evidence for scattered Neolithic, Bronze Age and Iron Age settlement nearby, but until a bridge was built there, London did not exist.^[5] Two ancient fords were in use a few miles upstream, beyond the river's upper tidal reach. They were aligned with the course of Watling Street and led into the heartlands of the Catuvellauni, who at the time of Caesar's invasion of 54 BC were Britain's most powerful tribe. Some time before Claudius' conquest of AD 43, power shifted to the Trinovantes, who held the region northeast of the Thames estuary from a capital at Camulodunum. The first London Bridge was built by the Roman military as part of a road-building programme to help consolidate their conquest.^[6]

Roman bridges

The first bridge was probably a Roman military pontoon type, giving a rapid overland shortcut to Camulodunum from the southern and Kentish ports, along the Roman roads of Stane Street and Watling Street (the A2). The Trinovantes submitted to Rome; a major colonia was imposed on Camulodunum, which became capital city of the new Roman province of Brittania. Around AD 55, this temporary bridge was replaced by a permanent timber piled bridge, maintained and guarded by a small garrison. On the relatively high, dry ground at the northern end of the bridge, a small, opportunistic trading and shipping settlement took root, and grew into the town of Londinium.^[7] A smaller settlement developed at the southern end of the bridge, in the area now known as Southwark. The bridge was probably destroyed along with the town in the Boudican revolt (60 AD), but both were rebuilt and Londinium became the administrative and mercantile capital of Roman Britain. The upstream fords and ferries remained in use but the bridge offered uninterrupted, mass movement of foot, horse, and wheeled traffic across the Thames, linking four major arterial road systems north of the Thames with four to the south. Just downstream of the bridge were substantial quays and depots, convenient to seagoing trade between Britain and the rest of the Roman Empire.^[8][9]