The first general post office in London opened in 1643, just 8 years after King Charles I legalized use of the royal posts for private correspondence. It was probably on Cloak Lane near Dowgate Hill. Coffee houses in the City such as Lloyd’s and Garraway’s organized private transport of mail among their patrons. The Royal Mail (which, following its legalization, held a nominal monopoly on such delivery services) moved its headquarters to Lombard Street in the City in 1678 to better curtail such practices.
After purchasing adjacent property in the centre of London’s financial district gradually became prohibitively expensive, the General Post Office purchased slums on the east side of St. Martin’s Le Grand and cleared them in order to establish a new headquarters, Britain’s first purpose-built mail facility. The General Post Office, designed with Grecian ionic porticoes by Sir Robert Smirke, was built between 1825 and 1829, ran 400 feet (120 m) long and 80 feet (24 m) deep, and was lit with a thousand gas burners at night.
In the mid-19th century there were four branch offices in London: one in the City at Lombard Street; two in the West End at Charing Cross and Old Cavendish Street near Oxford Street; and one south of the Thames in Borough High Street.
In the 1870s, a new building was added on the western side of the street to house the telegraph department, and the General Post Office North was built immediately north of the telegraph building in the 1890s. When the Central London Railway was built in 1900 its nearby station was named “Post Office”. Smirke’s building was felt to be too small by this time, however, and in 1910 the headquarters was moved to the King Edward Building. In 1912, the former GPO East was demolished: the current headquarters of BT, a post World War II building, occupies the site of the old Telegraph Office.
