Partition of Ireland
Beginning on 21 January 1919 with the Soloheadbeg ambush, through the Irish War of Independence, Irish republicans attempted to bring about the secession of Ireland from the United Kingdom of Great Britain and Ireland. Meanwhile, Irish unionistsmost of whom lived in the northeast of the islandwere just as determined to maintain the Union. The British Government, committed to implementing Home Rule, set up a cabinet committee under the chairmanship of southern unionist Walter Long. The Long Committee recommended the establishment of two devolved administrations, dividing the island into two territories: Northern Ireland and Southern Ireland. This was implemented as the Government of Ireland Act 1920. The act entered into force as a "" on 3 May 1921 and provided that Northern Ireland would consist of the six northeastern counties, while the remainder of the island would form Southern Ireland. It was intended that each jurisdiction would be granted home rule but remain within the United Kingdom. The government of Southern Ireland never functioned: the war for independence continued until the two sides agreed a truce in July 1921, ending with the Anglo-Irish Treaty on 6 December 1921.
Monarchy of the United Kingdom
In 1800, as a result of the Irish Rebellion of 1798, the Act of Union merged the kingdom of Great Britain and the kingdom of Ireland into the United Kingdom of Great Britain and Ireland. The whole island of Ireland continued to be a part of the United Kingdom until 1922, when what is now the Republic of Ireland won independence as the Irish Free State, a separate Dominion within the Commonwealth. The Irish Free State was renamed Éire (or "Ireland") in 1937, and in 1949 declared itself a republic, left the Commonwealth and severed all ties with the monarchy. Northern Ireland remained within the Union. In 1927, the United Kingdom changed its name to the United Kingdom of Great Britain and Northern Ireland, while the monarch's style for the next twenty years became "of Great Britain, Ireland and the British Dominions beyond the Seas, King, Defender of the Faith, Emperor of India".