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).
Very soon after the GNP&BR opened it was clear that the termination of the line in urban Finsbury Park rather than further out of central London in more suburban Wood Green, Southgate or Tottenham had been a mistake.