Revenue stamps of the United Kingdom
When Ireland was partitioned into Northern Ireland and Southern Ireland in 1921, separate revenue stamps were issued for both entities. Southern Ireland stamps saw little use since that political entity was quickly superseded by the Provisional Government of Ireland and later the Irish Free State (both of which applied overprints on various British and Irish revenue stamps). However, Northern Ireland continued to use separate revenue stamps until the 1980s. Northern Irish revenues include Civil Service, Dog Licence, Excise and National Insurance stamps, among many others.
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.