John Buchan, 1st Baron Tweedsmuir (1875-1940), was a Scottish novelist and a Unionist politician who served as Governor General of Canada. Buchan at first entered into a career in law in 1901, but almost immediately moved into politics, becoming private secretary to British colonial administrator Alfred Milner, who was high commissioner for South Africa, Governor of Cape Colony and colonial administrator of Transvaal and the Orange Free State. Buchan gained an acquaintance with the country that was to feature prominently in his writing. On his return to London, he became a partner in a publishing company while he continued to write books. In 1910, he wrote Prester John, the first of his adventure novels, set in South Africa. During World War I, he wrote for the War Propaganda Bureau and was a correspondent for The Times in France. In 1915, he published his most famous book The Thirty-Nine Steps, a spy thriller set just before the outbreak of World War I. The following year he published a sequel Greenmantle.