The London underground: a condensed history - The Guardian

1863
The world's first underground train line, the Metropolitan Railway, opens from Paddington to Farringdon Street.

1868
What became the District line opens between Westminster and South Kensington on Christmas Eve.

1869
The East London Line, then the East London Railway, opens between Wapping and New Cross.

1884
The Inner Circle (now Circle) line opens, connecting the Metropolitan and District lines.

1900
The Central line, then the Central London Railway, opens between Shepherd's Bush and Bank.

1905
The District and Circle lines switch from steam power to electricity.

1906
The Piccadilly line opens from Hammersmith to Finsbury Park and the Bakerloo opens between Baker Street and Kennington Road.

1911
Earl's Court becomes the first station to install the tube's now famous escalators.

1924
The Northern line opens, joining the City and South London Railway with the Charing Cross, Euston and Hampstead Railway.

1933
Draughtsman Harry Beck devises the first "diagrammatic" tube map, of the kind still used today.

1940
Tube platforms are used as air raid shelters throughout the second world war.

1953
A collision in the tunnels outside Stratford station kills 12 passengers.

1968
The Victoria Line opens after 25 years of planning and construction.

1975
The worst crash in the history of the tube kills 43 people at Moorgate station.

1979
The Jubilee line opens, running between Charing Cross and Baker Street.

1987
A fire at King's Cross station kills 31 people.

2003
Oyster cards are introduced and busking legalised in tube stations.

2005
The 7/7 terrorist attacks kill 39 passengers in tunnels near Liverpool Street, Edgware Road and King's Cross stations.

2007
The London Underground reaches a record one billion passengers in a single year.