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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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.
Outline of Northern Ireland
Northern Ireland was created as a distinct division of the United Kingdom on 3 May 1921 under the Government of Ireland Act 1920, although its constitutional roots lie in the 1800 Act of Union between Great Britain and Ireland.