Gospel Oak railway station is in the London Borough of Camden in north-west London. It is situated the North London Line, served by Mildmay line services between Clapham Junction/Richmond and Stratford, and is also the western passenger terminus of the Gospel Oak to Barking Line, served by Suffragette line services to/from Barking Riverside. Passengers using Oyster cards are required to tap on interchange Oyster card readers when changing between the two lines. The station is in Travelcard Zone 2, and is managed by London Overground which runs all passenger trains at the station.
The station opened in 1860 as Kentish Town on the Hampstead Junction Railway from Camden Road to Old Oak Common Junction south of Willesden Junction. It was renamed Gospel Oak in 1867 when a new station more appropriately named Kentish Town was opened about a kilometre south on the same line (that station is now Kentish Town West).
More information on the Wikipedia page [1]. The TfL page is [2]