 From December 1912 to October 1913 he was seconded to the Colonial Office in London, but then returned to Ceylon as private secretary to Governor Sir Robert Chalmers.In 1914 he married Chalmers's daughter, Mabel, and in 1915 he was promoted to Principal Assistant Colonial Secretary.In May 1917, Stevenson was appointed Chief Secretary of Cyprus, in which post he administered the government from November 1918 to August 1920, when he was appointed High Commissioner.