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 Italy Giolitti was Prime Minister five times between 1892 and 1921 and the second-longest serving Prime Minister in Italian history. Giolitti was a master in the political art of "trasformismo", the method of making a flexible, fluid centrist coalition in Parliament which sought to isolate the extremes of the left and the right in Italian politics. Under his influence, the Italian Liberals did not develop as a structured party. They were instead a series of informal personal groupings with no formal links to political constituencies. The period between the start of the 20th century and the start of World War I,