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
Records of Prime Ministers of the United Kingdom March 2036 (his 93rd birthday), he will surpass Callaghan's record and become the longest-lived Prime Minister. The shortest-lived Prime Minister was the Duke of Devonshire, who was born on 8 May 1720 and died on 2 October 1764 at the age of 44 years and 147 days. The Prime Minister who lived the longest after leaving office for the final time was the Duke of Grafton, who left office on 28 January 1770 and died on 14 March 1811, a total of 41 years and 45 days. In recent years, the Prime Minister who lived the longest after leaving office