A station on the Northern Line in Travelcard Zone 4 Opened 22 August 1867 (mainline services)as part of the Great Northern Railway's line between Finsbury Park and Edgware stations. As part of London Underground's Northern Heights plan, Northern line trains started serving the station in 1940 and main line passenger services ended in 1941. Known as Finchley & Hendon until 1894, Finchley (Church End) 1894-1940.
The Wikipedia page is [1] and the TfL page [2]. There are several videos.