The North London Railway (NLR) company had lines connecting the northern suburbs of London with the Port of London further east. The main east to west route is now part of London Overground's North London Line. Other NLR lines fell into disuse but were later revived as part of the Docklands Light Railway, and London Overground's East London Line. The company was originally called the East and West India Docks and Birmingham Junction Railway (E&WID&BJR) from its start in 1850, until 1853. In 1909, it entered into an agreement with the London and North Western Railway (LNWR) which introduced common management, and the NLR was taken over completely by the LNWR in 1922. The LNWR itself became part of the London, Midland and Scottish Railway (LMS) from the start of 1923. The railways were nationalised in 1948 and most LMS lines, including the North London route, then came under the control of the London Midland Region of British Railways.

The East and West India Docks and Birmingham Junction Railway was incorporated by an act of Parliament, the East and West India Docks and Birmingham Junction Railway Act 1846 (9 & 10 Vict. c. cccxcvi), on 26 August 1846. It was empowered to construct a railway from the district of Poplar and the docks to Camden Town in north London. The railway's headquarters and locomotive works were initially in Bow.

The North London Railway Act 1853 (16 & 17 Vict. c. xcvii) renamed the company to the North London Railway.

At first, it ran trains from Bow Junction on the London and Blackwall Railway (L&BR) to Islington, starting on 26 September 1850. The line was extended to Camden Town railway station from 7 December 1850 and to Hampstead Road station (later renamed Primrose Hill) from 9 June 1851. Another extension via the L&BR was opened on 1 January 1852, from Bow Junction to Poplar railway station, and from there to Blackwall and the East India Docks; a connection at Bow allowed trains to run to Fenchurch Street. This arrangement lasted until 1865, when an extension from Dalston Junction to Broad Street was opened; Broad Street became the main terminus, and the Poplar line became a branch. In the meantime, in 1864, a banker on a train from Fenchurch Street to Chalk Farm became the first victim of a murder on a British train.

In 1869, the line was extended along the North and South Western Junction Railway (a joint enterprise by the LNWR, Midland Railway and the NLR) from Willesden Junction to a London and South Western Railway branch to Richmond. A bypass line from Camden to Willesden Junction via Gospel Oak and West Hampstead opened in 1860. Meanwhile, at the eastern end, a spur line connecting the NLR to Stratford from Victoria Park opened in 1854 but was not used by passenger services. The line between Camden Town and Dalston Junction was quadrupled in 1871.

The LNWR took over the working of the railway under a common management arrangement on 1 February 1909. The company still existed until 1922, with its own board of directors and shareholders, when it was absorbed by the LNWR. The last board meeting and last shareholders meeting were both held on 23 November 1922, the latter giving the shareholders' approval of amalgamation. The board minutes were signed by A Holland-Hibbert, the chairman, who added "Goodbye!". Beneath this was typed, "This was the last Board Meeting of the North London Railway Company, the Undertaking being absorbed under “The London and North Western Railway (North London Railway and Dearne Valley Railway) Preliminary Absorption Scheme 1922” by the London and North Western Railway Company as from 1 January 1922."

The LNWR, which half-owned Broad Street station, was responsible for electrification of the Broad Street to Richmond and Kew Bridge lines in 1916.

The Kew Bridge service was withdrawn as a wartime economy measure in 1940, which proved to be permanent.