Partition of Ireland
The partition of Ireland () divided the island of Ireland into two distinct jurisdictions, Northern Ireland and Southern Ireland. It took place on 3 May 1921 under the Government of Ireland Act 1920. Today the former is still known as Northern Ireland and forms part of the United Kingdom, while the latter is now a sovereign state also named Ireland and sometimes called the Republic of Ireland.
Unionism in Ireland
In 1922, twenty-six counties of Ireland gained autonomy from the U.K. as the Irish Free State; in 1949, the State was declared to be a Republic and the last vestiges of royal power were abolished. The Republic of Ireland left the Commonwealth of Nations. The remaining six counties of the island of Ireland constituted the territory of Northern Ireland. In 1927, the realm, consisting of combined territories of Northern Ireland and Great Britain, was renamed the "United Kingdom of Great Britain and Northern Ireland". Today, unionism is almost exclusively an issue for Northern Ireland. It is concerned with the governance of and relationship between Northern Ireland and Great Britain.