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
Cabinet Secretary (Australian minister) 2007, Prime Minister Kevin Rudd created the new ministerial position of Cabinet Secretary with Australian Labor Party veteran Senator John Faulkner appointed conjointly as Special Minister of State to drive an integrity agenda. The position was carried over by Prime Minister Julia Gillard from 2010 to 2013 and again by Prime Minister Kevin Rudd in 2013. In 2015, Prime Minister Malcolm Turnbull resumed the ministerial position of Cabinet Secretary, broadening its responsibilities and including it in Cabinet. On the 18 January 2017, Prime Minister Malcolm Turnbull announced a ministerial reshuffle in which the position of Cabinet Secretary was disbanded and