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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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.
Postcolonial literature
A war of independence in the early 20th century was followed by the partition of the island, creating the Irish Free State in 1922, which became increasingly sovereign over the following decades, and Northern Ireland, which remained a part of the United Kingdom.