Editing London Bridge (section)

===Location===
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, London|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 [[Europe|Continental]] trade route from at least the 9th century BC.<ref>Merrifield, Ralph, ''London, City of the Romans,'' University of California Press, 1983, pp. 1–4. The terraces were formed by glacial sediment towards the end of the last Ice Age.</ref>

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.<ref>D. Riley, in Burland, J.B., Standing, J.R., Jardine, F.M., ''Building Response to Tunnelling: Case Studies from Construction of the Jubilee line Extension'', London, Volume 1, Thomas Telford, 2001, pp. 103 – 104.</ref> [[Watling Street#Westminster ford|A few miles upstream]], beyond the river's upper tidal reach, two ancient fords were in use. These were apparently aligned with the course of [[Watling Street]], which led into the heartlands of the [[Catuvellauni]], Britain's most powerful tribe at the time of [[Caesar's invasions of Britain#Second invasion (54 BC)|Caesar's invasion of 54&nbsp;BC]]. Some time before [[Claudius]]'s [[Roman conquest of Britain|conquest]] of AD&nbsp;43, power shifted to the [[Trinovantes]], who held the region northeast of the Thames Estuary from a capital at [[Camulodunum]], nowadays [[Colchester]] in Essex. Claudius imposed a major ''[[Colonia (Roman)|colonia]]'' at Camulodunum, and made it the capital city of the new Roman province of [[Britannia (Roman province)|Britannia]]. The first London Bridge was built by the Romans as part of their road-building programme, to help consolidate their conquest.<ref>The site of the new bridge determined the location of London itself. The alignment of Watling Street with the ford at Westminster (crossed via [[Thorney Island (Westminster)|Thorney Island]]) is the basis for a mooted earlier Roman "London", sited in the vicinity of [[Park Lane, London|Park Lane]]. See Margary, Ivan D., ''Roman Roads in Britain, Vol. 1, South of the Foss Way – Bristol Channel,'' Phoenix House Lts, London, 1955, pp. 46 – 47.</ref>