London’s first underground tube railway opened in 1870, under the Thames from Tower Hill to Pickleherring Street. Cable driven, it was a technical triumph but financial failure. In 1883 plans for a line from Borough to King William Street were revived and the City & South London Railway opened from Stockwell to KWS in 1890. A late switch to electric traction made it the world’s first underground electric tube railway.
This spawned a rush of applications for new lines, including the Great Northern & City [opened 1904], from Moorgate to Finsbury Park to relieve the Great Northern Railway’s suburban bottleneck.Some schemes floundered and were acquired by American tycoon Yerkes who injected them with American capital and equipment.
One was the proposed Charing Cross, Euston and Hampstead Railway with its branch to the Midland railway at Kentish Town. In 1902, Yerkes obtained powers to extend the branch to connect with the GNR near Highgate although the route north of Archway was not proceeded with. The CCE&HR opened in 1907.
Meanwhile, the C&SLR had been re-routed from Borough, tapping into London Bridge Station, and extended north to Angel in 1901, and to Euston in 1907.
When Yerkes acquired it in 1913, he held most of the network. He joined the C&SLR to the CCE&HR at Camden Town. To allow the use of standard rolling stock involved replacing all 22,000 C&SLR tunnel rings by a wider bore. The first through trains ran in 1924. The link under the Thames from Charing Cross to Kennington followed in 1926.
In 1933 under public control, plans to link the Northern line at Highgate were resurrected, together with electrification of the GNR, extension to Bushey and connection to the Moorgate relief line. The name Northern Line was adopted in 1937.
It was extended to East Finchley in 1939 and on to Barnet in 1941. Work was interrupted by the war and never restarted, although the single track to Mill Hill East was electrified during the war for access to the army barracks. Instead, the lines were closed down, leaving us with the Northern line familiar to us all.