Sir Robert Gordon Menzies, KT, AK, CH, QC, FAA, FRS (/ˈmɛnziːz/, MEN-zeez; 20 December 1894 – 15 May 1978) was an Australian politician who was the 12th and longest-serving prime minister of Australia, holding office for over 18 years from 1939 to 1941 and again from 1949 to 1966. He played a central role in the creation of the Liberal Party of Australia, defining its policies and its broad outreach.