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 Romania d'etat, followed by a constitutional referendum that replaced the Convention of Paris, an act that served as the constitution of the country, with his own version named the Statute expanding the Paris Convention (). The new constitution created the Senate for serving Cuza's legislative purposes and vested the office of the Prince with full executive authority, while the Prime Minister remained his subordinate. Even though Cuza now had plenary powers, the office the Prime Minister remained influent, and Mihail Kogălniceanu, the 3rd Prime Minister, a liberal and former ally of Cuza often clashed with him. After Cuza's removal by coup