His Majesty's Government (term)
The need became obvious with the Statute of Westminster 1931, which effectively made the Dominions equal constituent countries with the United Kingdom in the imperial project, and unavoidable with the transition of the Empire into the Commonwealth of Nations.
The term is employed in order to signify that the government of a Commonwealth realm or,[2] less commonly, a division thereof (for instance the Canadian Province of Alberta), belongs to the reigning sovereign, and not to the cabinet or prime minister.
Indeed, during the reign of Queen Anne (just before the development of the office of Prime Minister) her fondness for compromise and consensus frequently led to governments composed by persons who disliked each other and did not integrate.
The evolution of the British constitution and reduction in the powers of the Crown gradually reduced the centrality of the monarch in de facto government.
Queen Victoria was the last monarch truly to attempt to choose the personnel of her government; for instance her hatred of William Gladstone helped Lord Salisbury to retain office.
In the latter case this was only due to hung parliamentary arrangements, and (until the monarch's role was abolished in the 1960s) an unclear choice for leader of the Conservative Party.
Indeed, where the monarch has had discretion to choose a Prime Minister in such circumstances it has resulted in some controversy: for instance, George V's role in facilitating the formation of the National Government of the United Kingdom in 1931 because Ramsay MacDonald operated a minority government was not without controversy, whilst in Australia Sir John Kerr's (acting in loco regis as Governor-General) discretion in dismissing ministers led to a constitutional crisis.
Ironically, therefore, in the United Kingdom, precisely because it has a constitutional monarchy, the prime minister is referred to as the head of government, even though they do not, in fact, occupy such that exact role because of the position of the monarch.
