HISTORYIntroduction London Underground was formed in 1985, but its history dates back to 1863 when the world's first underground railway opened in London.Today, London Underground is a major business with three million passenger journeys made a day, serving 275 stations over 408 km (253 miles) of railway. In 2004-2005, London Underground trains ran a total of 69.4 million kilometres in passenger service.MilestonesKey dates Date Milestone1843 Opening of the Thames Tunnel, constructed by Sir Marc Brunel and his son Isambard. 1863The Metropolitan Railway opened the world's first underground railway on 10 January between Paddington (Bishop's Road) and Farringdon Street. 1868 Opening of the first section of the Metropolitan District Railway from South Kensington to Westminster (now part of the District and Circle Lines). 1869First steam trains travel through Brunel's Thames Tunnel1880Opening of the first Tube tunnel, from the Tower of London to Bermondsey. 1884Completion of what is now the Circle Line. 1890The City and South London Railway opened the world's first deep-level electric railway on 18 December, from King William Street in the City of London, under the River Thames to Stockwell. 1900Prince of Wales opens the Central London Railway from Shepherd's Bush to Bank (the "Twopenny Tube", now part of the Central Line). 1902Formation of the Underground Electric Railway Company of London (known as the Underground Group).Mergers brought all lines except the Metropolitan into the Group by the First World War. 1905District and Circle lines electrified. 1906Baker Street & Waterloo Railway (now part of the Bakerloo Line) opened from Baker Street to Kennington Road (now Lambeth North). Great Northern, Piccadilly & B...