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 Southern Ireland stamps saw little use since that political entity was quickly superseded by the Provisional Government of Ireland and later the Irish Free State (both of which applied overprints on various British and Irish revenue stamps).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.
Irish republicanism
In 1948, Fianna Fáil went out of office for the first time in sixteen years. John A. Costello, leader of the coalition government, announced his intention to declare Ireland a republic. The Republic of Ireland Act 1948, which "described" the state as the Republic of Ireland (without changing its name), led the British government to pass the Ireland Act 1949, which declared that Northern Ireland would continue as part of the United Kingdom unless the Parliament of Northern Ireland consented to leave; and Ireland ceased to be a member of the Commonwealth. As a result of this—and also because continuing struggle against the Dublin government was futile—the republican movement took the decision to focus on Northern Ireland from then on. The decision was announced by the IRA in its Easter statement of 1949.