After Eton, “Bush” Johnstone went up to Trinity College, Cambridge and was in the Cambridge boat for four years (1904-1907), being President of the Boat Cub in the last year. The following year he rowed in the Leander eight that won the gold medals at the Olympics. His other notable successes included wins in the Grand in 1904 and 1905 and the goblets in 1906, 1907 and 1909. In 1909, Johnstone joined the Government Survey Department in Ceylon but in 1913 he moved to the Administration of Zanzibar and on the outbreak of war initially served with the Carrier Corps in East Africa. After transferring to the Black Watch, he was awarded the OBE for services in France and Belgium. In his later years, Banner Johnstone was the rowing correspondent of the Daily Telegraph.