 Route 73 commenced on 30 November 1914, and originally ran from King's Cross to Barnes via Euston Road, Tottenham Court Road, Oxford Street, Knightsbridge, Kensington and Hammersmith.By 1949, the route had been extended at both ends to operate from Stoke Newington to Richmond.It was extended further west to Hounslow on 26 November 1958, replacing route 33.