In 1861 the South Eastern Railway Company obtained an Act of Parliament to extend its line from London Bridge station across the Thames to a new station on Cannon Street, right in the heart of the City. Sir John Hawkshaw, as consulting engineer to the company, designed the station, the bridge and the viaducts leading up to it. The bridge was originally called the Alexandra Bridge after the Danish princess who married the Prince of Wales shortly before work began in 1863. The bridge and station opened on 1 September 1863.The bridge had five spans of girders resting on fluted Doric cast-iron cylinders, four to each pier, and decorated brackets formed a sort of cornice. The bridge was originally 89 feet wide and carried five tracks, and there was a footpath cantilevered out on each side, the downstream one for railway staff, and the upstream one for the public, who had to pay a halfpenny toll. In 1878 the bridge was freed from toll, but the company later closed the footpath to the public, and it has never been replaced. There was talk about a new footbridge being added to the bridge to celebrate Queen Elizabeth II's Golden Jubilee, but the idea seems to have been quietly shelved.






During 1889-92 the bridge was widened to 120 feet to accommodate an extra five tracks, when Francis Brady added two cylinders to each pier on the upstream side at the same time removing the public footpath. In 1915—20 further strengthening work was carried out to carry heavier locomotives. In the late 1970s the bridge was rebuilt by British Rail, and the number of tracks was reduced again to five. During the work much of the decorative cast iron was removed and the Doric capitals were replaced by concrete.






When Cannon Street station was built, the foundations of a substantial first-century AD Roman building were found, and it is thought it may have been the palace of the provincial governor. In medieval and Tudor times it was the site of the Steelyard, the trading centre of merchants of the Hanseatic League from Germany. In September 2005 the Duke of Kent unveiled a plaque on the downstream wall of the station, overlooking the Thames Path, to commemorate this fact.The station, by Sir John Hawkshaw and Sir John Wolfe-Barry, had an arched iron and glass roof that was taller than the roof of St Pancras station. The only parts of the original station still standing are the distinctive pair of towers on either side of the platforms, and the side walls. The towers were built to house water tanks used to operate lifts. As part of the scheme there was a hotel on Cannon Street, designed by E. M. Barry in the Italianate style, but this was replaced in the 1 960s with an office block by the notorious architect John Poulson, who was later jailed for corruption and bribery. In the 1980s the station roof was replaced by another office block, whose piles were driven through the station platforms. In 2007 it was announced that the railway and Underground stations, as well as the offices above are to be refurbished, though the station will continue to operate during the redevelopment.