Revenue stamps of Northern Ireland
Upon the partition of Ireland in 1921, separate revenue stamps began to be issued for both Northern Ireland and Southern Ireland. The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century. The need for separate issues for Northern Ireland came about since taxes raised there were meant to remain in the country. Most Northern Irish revenue stamps were British key types with appropriate inscriptions, but there were a number of different issues as well.
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.