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 Southern Ireland stamps saw little use since that political entity was quickly superseded by the Provisional Government of Ireland and later the Irish Free State (both of which applied overprints on various British and Irish revenue stamps).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.
Northern Ireland Office
Before the partition, Ireland was governed through the Dublin Castle administration and the Home Office was also responsible for Irish affairs. From 1924 to 1972, Northern Ireland affairs were handled by the Northern Ireland Department of the Home Office. In August 1969, for example, Home Secretary James Callaghan approved the sending of British Army soldiers to Northern Ireland.