Prime Minister of Australia prime minister, otherwise William McMahon63. Robert Menzies was the oldest person to ever be prime minister, leaving office at 71 years old. The longest-serving Prime Minister was Sir Robert Menzies, who served in office twice: from 26 April 1939 to 28 August 1941, and again from 19 December 1949 to 26 January 1966. In total Robert Menzies spent 18 years, 5 months and 12 days in office. He served under the United Australia Party and the Liberal Party respectively. The shortest-serving Prime Minister was Frank Forde, who was appointed to the position on 6 July 1945 after the death of
Prime Minister of Greece War. Prime Minister of Greece The Prime Minister of the Hellenic Republic (, "Pro̱thypourgós ti̱s Elli̱nikí̱s Di̱mokratías"), colloquially referred to as the Prime Minister of Greece (, "Pro̱thypourgós ti̱s Elládas"), is the head of government of the Hellenic Republic and the leader of the Greek cabinet. The incumbent prime minister is Alexis Tsipras, who took office on 21 September 2015. The prime minister's official seat (but not residence) is the Maximos Mansion in the centre of Athens. The office is described in the Constitution either as Prime Minister or President of the Government (Πρόεδρος της Κυβερνήσεως). This is the reason