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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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.
Scottish independence
The United Kingdom of Great Britain and Ireland was formed by the Acts of Union 1800, which united the Kingdom of Great Britain and the Kingdom of Ireland. The 26 southern counties of Ireland left the Union in 1922, which became known as the United Kingdom of Great Britain and Northern Ireland.