From 16 March 1899, the Great Central Railway served the station through its extension to Marylebone. Consequently, the station became joint Met/GCR owned. On 1 January 1923, the GCR became part of the London and North Eastern Railway (LNER) as part of the Railways Act 1921, and on 1 July 1933, the Met became part of the London Passenger Transport Board (LPTB), thus becoming the Metropolitan line of the London Underground. On 1 January 1948, the LNER was nationalised, its share of the station initially coming under the control of the Eastern Region of British Railways, before being transferred to the London Midland Region in 1958.