A bridge stood across the Thames at London from the time of the Romans and was subsequently replaced several times during the Saxon times. London Bridge remained the only crossing over the Thames in the London area until the construction of Westminster Bridge in 1750.
The last of the Saxon bridges was severely damaged by a flood in 1097 and again in the great fire of 1136 but was probably repaired enough that it could continue to be used. Between 1176 and 1209 a replacement was built slightly upstream to the west, in line with Fish Street Hill, in the position it occupied for the following seven hundred years. It was built under the supervision of a parish priest, Peter of St.Mary Colechurch.
The foundations of the new stone bridge were constructed by ramming wooden stakes into the river bed and infilling with rubble. Kentish ragstone, Purbeck stone from Dorset and Reigate stone from Surrey were all used. With nineteen broad-pointed arches, ranging from fourteen feet to thirty two feet in width, it was for many years the longest stone bridge in England. Nine hundred and twenty-six feet in length and forty feet in width, it stood sixty feet above the water level. London Bridge became an impressive sight, the most magnificent such structure in Britain, although shorter than others at towns such as Avignon and Rouen.
The bridge was erected on piers that in turn stood on starlings set close together. They formed a barrier to the incoming and outgoing tides, creating a weir effect. That made it difficult to navigate, even for vessels small enough to fit between the piers. Taking a boat through while the tide was flowing was described as ‘shooting the bridge’ and could be very dangerous. In his Chronicle of London, William Gregory describes an incident in about 1428: “The vij [7th] day of Novembyr the Duke of Northefolke wolde have rowed thoroughe the brygge of London, and hys barge was rentte agayne the arche of the sayde brygge, and there were drowned many men, the nombyr of xxx  personys and moo of gentylmen and goode yemen [yeomen]”.
With the outgoing tide held back, the slower-moving water upstream froze over in cold winters, such as in 1262, allowing for the possibility of frost fairs. The river froze over for fourteen weeks in the cold winter of 1410 and again in 1434 when ships had to unload at Gravesend. Ice floes could cause serious damage to the bridge. In 1281 the ice on the frozen river was so thick that it caused five of the arches to collapse.
A drawbridge between the sixth and seventh piers from the southern end could be raised twice each day, when the tide was high, to allow for the passage of ships. The amount of tolls collected indicates that around two thousand ships passed through the bridge each year. Yet by the 15th century that had reduced to about once every three days, perhaps because tall boats were less likely to pass the bridge by then. The drawbridge could also be raised on the occasions that London came under attack. It was operated from a stone tower on its northern side, variously known as the ‘Great Gate’ or ‘Traitor’s Gate’. The original tower was rebuilt in 1426 from the legacy of the late Richard Whittington.
At the Southwark end of the bridge stood a tower with a gate to provide additional protection for London. It was closed to Simon de Montfort and his men in 1263 but battered down, allowing his army to enter the city. According to the Elizabethan historian John Stow: “This gate, with the tower thereupon, and two arches of the bridge, fell down…in the year 1436; towards the building whereof divers charitable citizens gave large sums of money.”
It may well be that Peter’s motivation in creating the bridge was the establishment of a new church, which appears to have been planned from the beginning. St.Thomas of the Bridge was built on the downstream side in the centre of London Bridge, dedicated to Thomas Becket, a 12th century parishioner of St.Mary Colechurch who had been canonised only three years before construction began. The church consisted of an upper chapel, raised slightly above road level, and a crypt built into the bridge. The lower level appears to have been completed at an early stage, with the upper part added in the latter part of the 14th century when records show a large amount of work was carried out. Peter died in 1205, before his work in building the bridge was completed, and he was buried in the crypt. By the mid-14th century four chaplains were occupied at St.Thomas of the Bridge.
The bridge was badly damaged and its original chapel destroyed in a fire that started at Southwark and spread right across to the northern bank in July 1212. A large crowd that gathered to witness the conflagration became trapped and many died as a result of burns or drowning.