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 Brazil Minister is surpassed by the total duration of the four non-consecutive premierships of the Marquis of Olinda, making Olinda the longest serving President of the Council if non-consecutive time is considered. The position of prime minister was abolished with the deposition of the Monarchy in 1889. The events of the Brazilian Proclamation of the Republic on November 15, 1889 started as an unprecedented military coup to remove the Prime Minister, who had been appointed by the Emperor and who enjoyed the confidence of the Chamber of Deputies, the lower house of the General Assembly, the Empire's Parliament; Marshal Deodoro da