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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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.
Provinces of Ireland
The earliest recorded mention of the major division of Ireland is in the Ulster Cycle of legends, such as the "Táin Bó Cúailnge". The "Táin" is set during the reign of "Conchobar Mac Nessa", king of Ulster, and is believed to have happened in the 1st century. In this period Ireland is said to have been divided into five independent over-kingdoms, or "cuigeadh" whose "rí" (kings) were of equal rank, not subject to a central monarchy. Pseudo-historians called this era "Aimser na Coicedach", which has been translated as: "Time of the Pentarchs"; "Time of the Five Fifths"; and "Time of the provincial kings". It was also described as "the Pentarchy".