When the Great Northern, Piccadilly and Brompton Railway (GNP&BR, precursor of the Piccadilly Line) opened in December 1906, its northern terminus was at Finsbury Park where it had an interchange with the Great Northern Railway (GNR) and the Great Northern & City Railway (GN&CR). To obtain approval for the railway's construction, the GNP&BR had, like the GN&CR before it, had to accept a GNR veto over further extensions north in competition of latter's suburban passenger services from King's Cross.