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 and in British colonial territories as they developed self-government. In some places alternative titles such as "premier", "chief minister", "first minister of state", "president of the council" or "chancellor" were adopted, but the essentials of the office were the same. By the late 20th century, the majority of the world's countries had a prime minister or equivalent minister, holding office under either a constitutional monarchy or a ceremonial president. The main exceptions to this system have been the United States and the presidential republics in Latin America modelled on the U.S. system, in which the president directly exercises executive authority.