Monarchy of Ireland

Monarchical systems of government have existed in Ireland from ancient times. In most of Ireland, this continued until 1949, when it transitioned to being the Republic of Ireland. Northern Ireland, as part of the United Kingdom, remains under a monarchical system of government.

The office of High King of Ireland effectively ended with the Norman invasion of Ireland (1169–1171) in which the island was declared a fief of the Holy See under the Lordship of the King of England. In practice, conquered territory was divided amongst various Anglo-Norman noble families who assumed title over both the land and the people with the prior Irish inhabitants being either displaced or subjugated under the previously alien system of serfdom. Though the revolutionary change in the status quo was undeniable, the Anglo-Norman invaders would fail to conquer many of the Gaelic kingdoms of Ireland, which continued to exist, often expanding for centuries after, however none could make any viable claims of High Kingship. This lasted until the Parliament of Ireland conferred the crown of Ireland upon King Henry VIII of England during the English Reformation. Henry initiated the Tudor conquest of Ireland which ended Gaelic political independence from the English monarch who now held the crowns of England and Ireland in a personal union.

The Union of the Crowns in 1603 expanded the personal union to include Scotland. The personal union between England and Scotland became a political union with the enactments of the Acts of Union 1707, which created the Kingdom of Great Britain. The crowns of Great Britain and Ireland remained in personal union until it was also ended by the Acts of Union 1800, which united Ireland and Great Britain into the United Kingdom of Great Britain and Ireland in January 1801.

In December 1922, most of Ireland seceded from the United Kingdom, becoming the Irish Free State; at the same time, the newly created Northern Ireland, which covered most of Ulster, remained part of the United Kingdom. As a dominion within the British Empire, the Free State legally retained the same person as monarch as the United Kingdom-which in 1927 changed its name to the United Kingdom of Great Britain and Northern Ireland. In 1937, the Free State adopted a new constitution that removed all mention of the monarchy. In April 1949, the former Free State, which covered most of Ireland, declared itself a republic, and withdrew from the Commonwealth of Nations; this left Northern Ireland as the only part of the island that retained a monarchical system.