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 Slovakia Prime Minister of Slovakia The Chairman of the Government of the Slovak Republic (), also known as the Prime Minister (), is the head of the Government of Slovakia. On paper he is the third highest constitutional official in Slovakia after the President of Slovakia and the Speaker of the National Council. In practice, he is the country's leading political figure. The office itself was created in 1969 and since then there has been 14 prime ministers serving in the office. Since 1993, when independent Slovakia emerged, seven prime ministers (five individuals only) have been serving in the office. On