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 Yugoslavia from Bosnia and Herzegovina by birth, was a politician of Croatia like Špiljak and Planinc, serving (at different times) as both prime minister and president of the presidency of that federal unit. Prime Minister of Yugoslavia The Prime Minister of Yugoslavia was the head of government of the Yugoslav state, from the creation of the Kingdom of Serbs, Croats and Slovenes in 1918 until the breakup of the Socialist Federal Republic of Yugoslavia in 1992. The Kingdom of Serbs, Croats and Slovenes was created by the unification of the Kingdom of Serbia (the Kingdom of Montenegro had united with Serbia