The route 63 first commenced operation on 17 September 1919 between Gospel Oak(Mansfield) and Honor Oak (Forest Hill Tavern) via Blackfriars Bridge and Elephant & Castle. By the end of World War II it had been cut back to operate between Kings Cross and Honor Oak. From 15 September 1954, the 63 was extended from Honor Oak to Crystal Palace as a replacement for the British Railways Crystal Palace Branch, which was closed at the same time. Apart from pre-war extension's northwards, as well as in the 1960s replacing withdrawn trolleybuses to Hampstead Heath and Parliament Hill Fields, the 63 has remained a very stable route. In 2003, the 1954 Crystal Palace extension was again withdrawn, being covered over that section by a related Route 363. The 63 has now returned to its 1945 routing.
