Highgate station was originally constructed by the Edgware, Highgate and London Railway in the 1860s on its line from Finsbury Park to Edgware. Before the line was opened it was purchased in July 1867 by the larger Great Northern Railway (GNR), whose main line from King's Cross ran through Finsbury Park on its way to Potters Bar and the north. The railway to Edgware opened as a single-track line on 22 August 1867.
Because of the hilly terrain, the station was built in a deep cutting excavated from Highgate Hill adjacent to Archway Road. Tunnels penetrated the hillside at each end of the station, leading to East Finchley to the north and Crouch End to the south.
A branch line was constructed from Highgate to Alexandra Palace by the Muswell Hill Railway (MHR) and opened on 22 May 1872. The new branch split from the original route north of the station in a wide arc around Highgate Wood. The next station on the branch line when it opened was Muswell Hill, and in 1902 an intermediate station opened at Cranley Gardens.
Because of the war the full plan for the reconstruction of the station designed by Charles Holden was not completed and parts for escalators intended for Highgate were used in central London stations. Works to electrify the LNER tracks from Finsbury Park, through Highgate to East Finchley and on the Alexandra Palace branch had been well advanced when war started but were postponed.
LNER trains continued to serve the High Level station, with services to East Finchley continuing until 2 March 1941. After that date LNER trains operated between Finsbury Park and Alexandra Palace only. The start of Underground services between Finchley Central and Mill Hill East in May 1941 was the last part of the Northern Heights Project to be completed.
After the war, maintenance works and reconstruction of war damage on the existing network had the greatest call on London Underground funds. Funds for new works were severely limited and the priority was given to the completion of the Central Line extensions to West Ruislip, Epping and Hainault. It was announced in October 1950 that the extension to Bushey Heath would not be proceeded with, but that extensions to Brockley Hill and beyond Mill Hill East might still proceed. In February 1954 it was finally announced that the extensions beyond Edgware and Mill Hill East had been abandoned. In October 1956 the depot buildings that had been built at Aldenham, in anticipation of the Bushey Heath extension, opened instead as London Transport's bus overhaul facility.
After a temporary closure between October 1951 and January 1952, British Railways (the successor to the LNER) ended services between Finsbury Park and Alexandra Palace permanently on 3 July 1954.
The high level station still remains above the live sation, and is still owned by London Underground. The tracks have been removed but the platforms and tunnels are still intact.
