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 Southern Ireland stamps saw little use since that political entity was quickly superseded by the Provisional Government of Ireland and later the Irish Free State (both of which applied overprints on various British and Irish revenue stamps).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.
Military history of Ireland
Until 1922 secret societies, popular risings and guerilla warfare came in sporadic outbreaks in attempts to end the 1801 union of Ireland and Great Britain. Between 1919–1922 the War of Independence brought the negotiation of the Anglo-Irish Treaty and the majority of Ireland seceded from the United Kingdom to form an independent state, which immediately fell into a civil war between opposing republican factions. The northern portion of the country would form Northern Ireland becoming an autonomous part of the United Kingdom.