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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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.
Irish revolutionary period
Unwilling to negotiate any understanding with Britain short of complete independence, the Irish Republican Army, the army of the newly declared Irish Republic, waged a guerilla war (the Irish War of Independence) from 1919 to 1921. In the course of the fighting and amid much acrimony, the Fourth Government of Ireland Act 1920 implemented Home Rule while separating the island into what the British government's Act termed "Northern Ireland" and "Southern Ireland". In July 1921 the Irish and British governments agreed to a truce that halted the war. In December 1921 representatives of both governments signed the Anglo-Irish Treaty. The Irish delegation was led by Arthur Griffith and Michael Collins. This created the Irish Free State, a self-governing Dominion of the Commonwealth of Nations in the manner of Canada and Australia. Under the Treaty, Northern Ireland could opt out of the Free State and stay within the United Kingdom: it promptly did so. In 1922, both parliaments ratified the Treaty, formalising dominion status for the 26-county Irish Free State (which renamed itself "Ireland" and claimed sovereignty over the entire island in 1937, and declared itself a republic in 1949); while Northern Ireland, gaining Home Rule for itself, remained part of the United Kingdom. For most of the 20th century, each territory largely aligned to either Catholic or Protestant ideologies, although this was more marked in the six counties of Northern Ireland.Separate unionist and nationalist historical narratives exist for the historic events in question; nationalist perspectives are further divided by the Civil War which ended the revolutionary period. The Northern Ireland peace process, with its promotion of dialogue and reconciliation, has modified this separation. The Bureau of Military History established by the Irish government in 1947 collected oral history accounts from republican veterans of the period 1913 to 1921. Its records were sealed until the last veteran's death in 2003; they were published online in 2012.