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 Southern Ireland stamps saw little use since that political entity was quickly superseded by the Provisional Government of Ireland and later the Irish Free State (both of which applied overprints on various British and Irish revenue stamps).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.
Foreign relations of Ireland
Since at least the 1600s Ireland has had political connections with the United Kingdom, with the whole island becoming a part of the United Kingdom of Great Britain and Ireland from 1801 to 1922. From the time of Ireland declaring itself independent from the United Kingdom in 1937, the two countries have been involved in a dispute over the status of Northern Ireland. Articles 2 and 3 of the Constitution of Ireland formerly claimed Northern Ireland as a part of the ""national territory"", though in practice the Irish government did recognise the UK's jurisdiction over the region.
From the onset of the Troubles in 1969, the two governments sought to bring the violence to an end. The Sunningdale Agreement of 1973 and the Anglo-Irish Agreement of 1985 were important steps in this process. In 1998, both states signed the Good Friday Agreement and now co-operate closely to find a solution to the region's problems. Articles 2 and 3 of the Constitution of Ireland were amended as part of this agreement, the territorial claim being replaced with a statement of aspiration to unite the people of the island of Ireland. As part of the Good Friday Agreement, the states also ended their dispute over their respective names: "Ireland" and the "United Kingdom of Great Britain and Northern Ireland". Each agreed to accept and use the others' correct name.