The London Underground Northern line is a London Underground line that runs between North London and South London. It is printed in black on the Tube map. It carries more passengers per year than any other Underground line – around 340 million in 2019 – making it the busiest tube line in London. The Northern line is unique on the Underground network in having two different routes through central London, two southern branches and two northern branches. Despite its name, it does not serve the northernmost stations on the Underground, though it does serve the southernmost station at Morden, the terminus of one of the two southern branches also the line got two new stations. The line's northern termini, all in the London Borough of Barnet, are at Edgware and High Barnet; Mill Hill East is the terminus of a single-station branch line off the High Barnet branch. The two main northern branches run south to join at Camden Town where two routes, one via Charing Cross in the West End and the other via Bank in the City, continue and then join at Kennington in Southwark. At Kennington the line again divides into two branches, one to each of the southern termini – at Morden, in the borough of Merton, and at Battersea Power Station in Wandsworth. For most of its length the Northern line is a deep tube line. The portion between Stockwell and Borough opened in 1890 and is the oldest section of deep-level tube line on the network. Nearly 340 million passenger journeys were recorded in 2019 on the Northern line, making it the busiest on the Underground, although this is distorted due to having 2 branches within Central London, both of which are less busy than the core sections of other lines. It has 18 of the system's 31 stations south of the River Thames. There are 52 stations in total on the line, of which 38 have platforms below ground. The line's structure of two northern branches (one with a further short branch), two central branches, and two southern branches reflects its complicated history. The core of the line, including the two central branches and the beginnings of the two northern branches, was constructed by two companies, the City and South London Railway and the Charing Cross, Euston and Hampstead Railway, in the 1890s and 1900s. The companies came under the same ownership in 1913, and were physically connected and operationally merged in the 1920s, while at the same time extensions to Edgware and Morden were completed. In the 1930s and 1940s the Northern line took over and electrified the London and North Eastern Railway branches to Mill Hill East and High Barnet. This was the final extension of the line for eight decades, though between the 1930s and 1970s the Northern City Line was branded and operated as part of the Northern line despite being disconnected from the rest of the line. The most recent extension, a second southern branch from Kennington to Battersea, opened on 20 September 2021. There are proposals to split the line into two separate lines. Route Map Also includes Branches to Edgware, Mill Hill East and Battersea Power Station and goes via Charing cross. Station List Morden - High Barnet Morden South Wimbledon Colliers Wood Tooting Broadway Tooting Bec Balham Clapham South Clapham Common Clapham North Stockwell Oval Kennington Elephant & Castle Borough London Bridge Bank Moorgate Old Street Angel Kings Cross. St Pancras Euston Mornington Crescent Camden Town Kentish Town Tufnell Park Archway Highgate East Finchley Finchley Central West Finchley Woodside Park Totteridge & Whetstone High Barnet To Edgware (Starting from Camden Town) Chalk Farm Belsize Park Hampstead Golders Green Brent Cross Hendon Central Colindale Burnt Oak Edgware To Mill Hill East Mill Hill East To Battersea Power Station Nine Elms Battersea Power Station Via Charing Cross (Between Kennington and Elephant & Castle) Waterloo Embankment Charing Cross Leicester Square Tottenham Court Road Goodge Street Warren Street (Towards Morden/ High Barnet) Rolling Stock 1995 Stock That's all Route Hopping London Underground Bakerloo Line Route Hopping at Waterloo, Embankment or Elephant and Castle to the Bakerloo Line route London Commuter (Brighton Main Line) Route hop at Balham station to the brighton main line route WCML South Route Hop at Euston station to the WCML South route Mastery Rewards Tier 1 London Underground Northern Line Decals Tier 2 Retired 1959 Stock List of Information about the route Termini Kennington, Battersea Power Station, Morden Edgware, High Barnet, Mill Hill East Stations 52 Colour on map Black Website tfl.gov.uk Type Rapid transit System London Underground Depot(s) Golders Green/ Morden Stabling Sidings: Highgate/ Edgware/ High Barnet Ridership 339.7 million passenger journeys (2019) Opened 18 December 1890; 134 years ago (as City and South London Railway) 22 June 1907; 117 years ago (as Charing Cross, Euston & Hampstead Railway) 13 September 1926; 98 years ago (Lines merged) 28 August 1937; 87 years ago (Renamed to Northern line) Last extension 20 September 2021 Line length 58 km (36 mi) Character Deep-tube Track gauge 1,435 mm (4 ft 8+1⁄2 in) standard gauge Electrification Fourth rail, 630 V DC Operating speed 45 mph (72 km/h) Signalling CBTC (SelTrac) Thanks for taking your time to read this suggestion, and feel free to discuss below, it really helps.