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 Bangladesh by political instability and economic difficulties. The nascent democratic institutions foundered in the face of military intervention in 1958, and the government imposed martial law between 1958 and 1962, and again between 1969 and 1971. Between 1947 and 1971 it was intermittently governed by Governors and Chief Minister of East Pakistan. The modern office of Prime Minister was established following the declaration of independence of East Pakistan with the Provisional Government of Bangladesh on 10 April 1971, of which Tajuddin Ahmad became the first Prime Minister of Bangladesh. Since the adoption of the current Constitution of Bangladesh in 1972 the