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 Vietnam Council of Ministers, the highest executive body of state, from 1981 until it was renamed to Government in the 1992 constitution. The office of prime minister was renamed in the 1980 constitution to that of Chairman of the Council of Ministers. Pham Van Dong, the second Prime Minister of Vietnam, served as North Vietnamese Prime Minister from 1955 until 1976, when he became prime minister of a unified Vietnam, and then until 1987, when he resigned. At his resignation, he was the longest-serving prime minister in Vietnamese history, and the oldest serving prime minister in the world. He often lamented