He became leader of the Conservative Party in 1911, and supported Ulster’s resistance to Home Rule. A tariff reformer, in 1915 he joined Asquith’s coalition as Colonial Secretary and continued under Lloyd George, serving as Chancellor of the Exchequer (1916–19) and Lord Privy Seal (1919–21). In 1922 the Conservatives rejected the coalition government of Lloyd George and he was appointed Prime Minister. He resigned the following May for reasons of ill health.