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 Cuba referred to as being the country's "prime minister". The incumbent since 19 April 2018 has been Miguel Díaz-Canel, who took over from Raúl Castro on that date. Prime Minister of Cuba The Prime Minister of Cuba () – official title: President of the Council of Ministers () – is the head of the Council of Ministers of Cuba. The office of Prime Minister was first instituted in 1940 in accordance with the provisions of the Constitution of Cuba as amended in that year. The first Prime Minister of Cuba was Carlos Saladrigas Zayas (1900–1957), the nephew of former President Alfredo