1906 - Elephant & Castle station opens
1915 - The line is extended from Baker Street to Queen's Park
1939 - The Bakerloo line takes over the Stanmore branch of the Metropolitan line
1979 - The Jubilee line opens and, after 40 years, the Stanmore branch of the Bakerloo line closes
1982 - The four peak period trains between Queen's Park and Watford Junction are withdrawn
1989 - Services between Queen's Park and Harrow & Wealdstone restart
Central Line
The Central Line, originally called the Central London Railway, opened on 30 July 1900 as a cross-London route from Bank to Shepherd's Bush.
Popular from the start, part of its success stemmed from the cost: a flat fare of two old pence to travel. This inspired the press to call it the 'Tuppenny Tube.'
In 1908, London hosted the Franco-British exhibition, the largest fair of its kind, which attracted 8 million visitors. At the time, the exhibition site was little more than a cluster of white buildings with no official name but when the Central line extended to the site, it officially became known as White City.
In the 1990s, the Central line was upgraded to automatic operation, making it the second Underground line, after the Victoria line in the 1960s, to use this technology.
Key Central line dates
1900 - Central London Railway opens
1908 - The line extends west to Wood Lane to support the White City Exhibition
1912 - The line extends east from Bank to Liverpool Street
1920 - The line extends west to Ealing Broadway
1945 - After the war, new tracks next to to the main line railway start to be used. They run from North Acton to West Ruislip and include new tunnels from Liverpool Street to Leyton
1994 - The Epping to Ongar shuttle service closes, due to low passenger numbers
Circle line
Although the first circular service started in 1884, the Circle line as we know it didn't really begin until the 1930s. The 'Circle line' name first appeared on a poster in 1936 but took another 13 years for it to get its own, separate line on the Tube map.
The tracks used by the Circle line were run by the Metropolitan Railway and District Railway, two companies who couldn't agree on how to run the line. Their differences initially meant that District Railway ran the clockwise trains and Metropolitan Railway, the anti-clockwise trains.
In December 2009, the Circle line was broken and replaced by an end-to-end service between Hammersmith and Edgware Road, via Aldgate.
Key Circle line dates
1884 - The first circular service begins
1868 - The Paddington to Farringdon (Metropolitan Railway) line extends to South Kensington. The District Railway opens its new line from South Kensington to Westminster at the same time
1884 - The District Railway line finally extends to Mark Lane (now Tower Hill). It meets the Metropolitan Railway line to create a full circle
1905 - The line is electrified
1933 - Metropolitan Railway and District Railway become part of the London Passenger Transport Board
1936 - The 'Circle line' name appears on a poster for the first time
1949 - The Circle line gets its own line on the Tube map
2009 - The Circle line is broken and replaced by and end-to-end service
District line
The District line first opened on Christmas Eve 1868, between South Kensington and Westminster.
In the years following, it extended both east and west, even going as far as Windsor. In 1883, the line was extended from Ealing Broadway to Windsor and has run services as far as Southend, during its time.
Uxbridge and Hounslow were part of the District line until they were transferred to the Piccadilly line in 1933 and 1964.
Key District line dates
1868 - The first section of what is now the District line begins. It runs between South Kensington and Westminster
1869 - New tracks open between Gloucester Road and West Brompton
1874 - The line extends to Hammersmith, Richmond in 1877 and Ealing Broadway in 1879
1885 - The two-year old Ealing to Windsor service ends
1884 - The line extends to Mark Lane (now Tower Hill)
1910 - The line extends to Uxbridge, following an earlier extension to Hounslow (in 1884)
Hammersmith & City line
Intended as a feeder to the Metropolitan line, with the extension running through fields on the fringes of suburbia to Hammersmith, The Hammersmith and City Railway opened on 13 June 1864. It wasn't until 1988, however, that it gained independence to become the Hammersmith & City line in its own right.
Jointly run by the Great Western Railway (GWR) and Metropolitan Railway (MR), when it opened, the only stations on the two-mile long track were Notting Hill (now Ladbroke Grove) and Shepherd's Bush.
Since the Circle line began running trains on the 'loop' in 2009, the Hammersmith & City line no longer has any unique stations. Every one of its 29 stations is shared with another tube line.
Key Hammersmith & City line dates
1863 - The Metropolitan Railway opens between Farringdon and Paddington
1864 - Together with Great Western Railways, Metropolitan Railway extends the line to Hammersmith
1864 - Services to Addison Road (now Kensington Olympia), via the curve at Latimer Road, begin. Following bomb damage in 1940, this service is suspended and doesn't restart after the war
1869 - A new London and South Western line opens between north of Addison Road and Richmond, via Ravenscourt Park. The new Hammersmith station (at Grove Road) means the old terminus is re-sited
1884 - The line extends east to Whitechapel
1906 - The line is electrified
1936 - Trains are extended over the former District Railway line to Barking
1988 - The line becomes the Hammersmith & City line in its own right
Jubilee line
Although a number of Jubilee line stations are among the Underground's newest, the line also serves some stations that originally opened over 100 years ago.
Inaugurated on 1 May 1979, the Jubilee line linked new tunnels across central London (stretching for 4 kilometres between Baker Street and Charing Cross with the former Bakerloo line branch north of Baker Street to Stanmore).
The northern end of the line had previously been part of the Metropolitan Railway, before transferring to the Bakerloo line in 1939 when a new section of twin tube tunnels between Baker Street and Finchley Road (including stations at St John's Wood and Swiss Cottage) also opened.
From 1979 Charing Cross was the line's southern terminus for two decades, but further extension to the Jubilee line was recommended in the East London Rail Study in 1989 with Royal Assent to the Bill obtained in March 1992.
Work started on the £3.5bn project to extend the Jubilee line in 1993. The Prime Minister at the time, John Major drove the first pile of the extension at a start-of-work ceremony at Canary Wharf on 8 December 1993. The extension from Green Park to Stratford was opened in three phases during 1999. The extended Jubilee line was finally joined to the existing line on 20 November 1999, although Westminster was the last station on the line to be opened on 22 December 1999.
Since its opening, the Jubilee line extension has facilitated and contributed to the significant growth of London's Docklands as a centre for business, residential and leisure activity.
Metropolitan line
Opened in 1863, The Metropolitan Railway between Paddington and Farringdon was the first, urban, underground railway in the world. An extension from Baker Street to Swiss Cottage in 1868, however, put an end to this claim to fame.
With the growth of suburban areas in the north west of London, Buckinghamshire, Hertfordshire and Middlesex (dubbed 'Metroland'), in the 20th century, Metropolitan Railway spotted a marketing opportunity: by promoting dream homes in the countryside, they could also highlight their own fast, rail services to get people there.
As the owners of surplus land, Metropolitan Railway were in a position to branch out into real estate, and by 1919 they were developing housing under the name of Metropolitan Railway Country Estates Limited.
Metroland was immortalised in the 1973 BBC TV documentary, narrated by the then Poet Laureate, Sir John Betjeman.
Key Metropolitan line dates
1863 - The line opens between Paddington and Farringdon
1868 - The line extends from Baker Street to Swiss Cottage
1892 - Line extensions reaches Aylesbury
1904 - The Uxbridge branch opens
1905 - The first electric trains appear and are gradually introduced across the whole line, apart from the line beyond Rickmansworth
1925 - The Watford branch opens
1932 - Another branch, to Stanmore opens, but this becomes part of the Bakerloo line in 1939
1961 - The steam trains operating north of Rickmansworth stop as the line is electrified to Amersham and Chesham. Services beyond Amersham are taken over by British Rail (now Chiltern Railways)
2012 - A new fleet of electric trains are introduced, the first on the Underground to feature air conditioning and full-length, walk-through interiors
Northern line
The Northern line, opened in 1937, was created out of two separate railways: the City and South London Railway, and the Charing Cross, Euston and Hampstead Railway.
It expanded a little but WWII slowed the expansions down. Scheduled plans to extend to Mill Hill, Brockley Hill, Elstree and Bushey Heath (known as the Northern Heights plan), suffered post-war restrictions and never recovered. These plans were finally dismissed in 1954.
Key Northern line dates
1890 - City & South London Railway opens - it runs from King William Street (near Bank) to Stockwell
1907 - Charing Cross, Euston and Hampstead Railway (Hampstead Railway, as it's called) opens. It runs from the Strand (Charing Cross) to Golders Green, with a branch from Camden Town to Highgate
1921 - Hampstead Railway extends to Edgware
1922 - City and South London Railway links to the Hampstead Railway at Camden Town
1926 - City and South London/Hampstead Railway extends south to Morden and Kennington
1933 - City and South London/Hampstead Railway become the Northern line
1939 - 1941 The new Northern line extends between Archway and East Finchley, High Barnet and Mill Hill East
1975 - The tunnelled link between Finsbury Park and Moorgate, via Essex Road, is transferred to British Rail (now First Capital Connect)
Piccadilly line
The Piccadilly line opened as the Great Northern, Piccadilly & Brompton Railway on 15 December 1906 and it ran between Finsbury Park and Hammersmith.
The line remained much the same until the 1930s when it expanded rapidly, incorporating stations which are now regarded as classic examples of period architecture. Arnos Grove, Southgate and Sudbury Town, for example, are listed buildings.
The development of Heathrow Airport has also been a reason for expansion, with Heathrow Terminals 1-5 opening between 1977 and 2008. When Terminal 5 opened in 2008, it became the first stretch of new Underground railway in London since the Jubilee line extension in 1999.
Key Piccadilly line dates
1906 - The line opens between Finsbury Park and Hammersmith
1907 - A branch line from Holborn to Aldwych opens
1932 to 1933 - The line extends to South Harrow, Arnos Grove, Hounslow West, Uxbridge and Cockfosters
1977 - Heathrow Terminals 1, 2 and 3 open
1986 - The Heathrow service becomes a loop with the opening of Terminal 4
1994 - The Aldwych branch of the Piccadilly line closes down because of too few passengers and high costs
2008 - Heathrow Terminal 5 opens
Victoria line
Built at the end of the 1960s, the main aim of the Victoria line was to connect four, main line terminals: Euston, St. Pancras, King's Cross and Victoria, although its origins go back to 1943.
Future hopes for the Victoria line were included in a document called the County of London Plan, but war and post-war constraints mean that the plans continued to be put on hold.
Parliamentary Powers to build the line were obtained in 1955 but difficulties with funding meant that actual construction work didn't start until 1962.
The Victoria line opened in stages between 1968 and 1971, and reached areas of north and south London that had never had an Underground station before.
The line was the first automatic passenger railway in the world, fully equipped with an Automatic Train Operation system (ATO). Such technology meant that at the touch of a button, the train doors would close and drive automatically to the next station, guided by coded impulses transmitted through the track.
The original 1968 line received a complete upgrade in 2012.
Waterloo & City line
In 1898, the Waterloo & City line (or 'Drain' as it was known), became London's second, deep-level Tube railway.
Initially, it was promoted by the London and South Western Railway company, whose trains terminated at Waterloo. The new line's selling point was that it could offer commuters a direct rail link to and from the City of London.
Wooden-built trains ran on the line until 1940 but were replaced by specially-designed, Tube-sized cars based on the technology of the Southern Railway's trains, but these too were eventually replaced in 1994.
In the post-war years, the Waterloo & City line became part of British Railways but it transferred to London Underground in 1994, when it became (at that time), the Underground's 12th line.