Upon retirement, it is customary for the sovereign to grant a prime minister some honour or dignity. The honour bestowed is commonly, but not invariably, membership of the UK's most senior order of chivalry, the Order of the Garter. The practice of creating a retired prime minister a Knight of the Garter (KG) 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.