Prime Minister of the United Kingdom senior order of chivalry, the Order of the Garter. The practice of creating a retired Prime Minister a Knight (or, in the case of Margaret Thatcher, a Lady) of the Garter (KG and LG respectively) has been fairly prevalent since the mid-nineteenth century. Upon the retirement of a Prime Minister who is Scottish, it is likely that the primarily Scottish honour of Knight of the Thistle (KT) will be used instead of the Order of the Garter, which is generally regarded as an English honour. Historically it has also been common for Prime Ministers to be granted a peerage upon
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