Monarch of the United Kingdom

The monarch of the United Kingdom is the head of state of the United Kingdom and its overseas territories in the broader Commonwealth of Nations. While the monarchy maintains formal executive authority over the country, those powers are constrained by law, precedent, and custom. For example, while the monarch appoints the prime minister, custom dictates that the monarch must appoint someone who has the support of the House of Commons. Thus, the Prime Minister's tenure in office is set by democratic election rather than by the monarch's choice. Moreover, the Prime Minister holds most of the actual power when it comes to setting and executing domestic and foreign policy.

In addition, the monarch is the Supreme Governor of the Church of England. Again, as in the secular realm, the monarch's role is more ceremonial, and the Archbishop of Canterbury is the true spiritual leader.

The monarch reigns for life. Succession is hereditary, and is governed by male-preference cognatic primogeniture. In October, 2011, the governments of the various commonwealths began the process of implementing legislation to do away with the male preference. Efforts are also being made to do away with the ban on Catholic rulers.

OTL
There have been twelve monarchs of United Kingdom proper, although the monarchy traces its origins back to both the monarchies of the Angles and the ancient Scots kings. The Kingdom of Great Britain was formed by the Acts of Union on 1 May 1707 with the merger of the Kingdom of England and the Kingdom of Scotland, which had been in personal union under the House of Stuart since March 1603. On 1 January 1801 Great Britain merged with the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland. After most of Ireland left the union on 6 December 1922, its name was amended to the United Kingdom of Great Britain and Northern Ireland on 12 April 1927.

Atlantis
During the reign of George III, Britain's holdings in Atlantis were expanded at the end of the French and Spanish War. However, Atlantis in its entirety successfully broke away in 1778 at the conclusion of the Atlantean War of Independence. Britain and at Atlantis fought another war in 1809 which was ultimately inconclusive.

The Atlantean Servile Insurrection took place concurrently with the reign of Victoria; Britain did not intervene in that conflict, however.

Southern Victory
The reign of Victoria saw Britain intervene in North America twice in a generation. In 1862, Britain recognized the independence of the Confederate States, and forced a mediation upon the United States, bringing the War of Secession to a close. In 1881, Britain participated in the Second Mexican War, attacking the USA on several fronts, and annexing a part of Maine when the conflict ended in 1882.

However, the UK's participation in the Great War (in the reign of George V) and the Second Great War (in the reign of Edward VIII) proved disastrous for the country, as Britain was defeated both times, and devastated with superbombs in the last one.

The Two Georges
In the mid-1760s, King George III met with an American delegation led by Colonel George Washington. From this meeting, an agreement on colonial self-rule within the British Empire averted a feared revolution of the colonies against Great Britain, and led to the foundation of the North American Union. A famous painting commemorated this event.

The Union continued as a proud part of the Empire, naming its capital after Queen Victoria. In 1995, a plot by a separatist terrorist group was thwarted in the capital, and the life of the visiting King Emperor Charles III was saved.

Literary comment
Although the initial Point of Divergence comes in 1763 or thereabouts, the list of British Monarchs does not seem to have diverged from OTL until 1936. George III plays an important background role, Victoria's reign is described in broad strokes (such as the naming of the Union capital), and passing references are made to Edward VIII and his brother. That last fact implies that there was an Edward VII, and also the existence and probable reign of George V.

A break happens after this point, as Edward VIII seems to have had a much longer reign than in OTL. A passing reference is made to Edward IX, and the current monarch Charles III appears as a significant character in the final chapters. The compact timeline between 1936 and the present day of 1995, suggests that Edward VIII, Edward IX, and Charles III succeeded each other directly, probably from fathers to sons. As Edward VIII never had children in OTL, the last two must be wholly fictitious. While Charles III strongly resembles Prince Charles of OTL, the previously stated logic indicates that he is an analog rather than the same man.

Other Monarchs
George VI reigns in Joe Steele (the novel), Worldwar and The War That Came Early. In both Joe Steele and in Worldwar, George plays a background role, leaving the actual running of the British government to Winston Churchill, as required by British law. In The War That Came Early, George's reign sees Britain enter a second World War against Germany in October, 1938, enter an alliance with Germany against the Soviet Union in 1940, then return to war with Germany in 1941 after a military coup removes the authoritarian government of Prime Minister Sir Horace Wilson. George gives his approval to the coup and the subsequent interim military government.

Elizabeth II is referenced as reigning in Colonization. Her coronation is mentioned in the unrelated short story, "Hindsight".

Henry IX is the reigning monarch in In the Presence of Mine Enemies. His lineage is unknown. He gives his blessing to the British Union of Fascists' decision to elect its leaders democratically in 2010.

An unidentified king reigns over the UK in the late 21st Century in Curious Notions.