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 The latter were withdrawn soon afterwards upon the establishment of the Provisional Government, but the former continued to issue revenue stamps until the late 20th century.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 Boundary Commission
The Government of Ireland Act 1920 was enacted during the height of the War of Independence and partitioned the island into two separate Home Rule territories of the United Kingdom of Great Britain and Ireland, to be called Northern Ireland and Southern Ireland. In its determination of this border, the Parliament of the United Kingdom heard the arguments of the Irish Unionist Party, but not those of most of the elected representatives of the Irish nationalist population. Sinn Féin refused to recognise any legitimate role of that Parliament in Irish affairs and declined to attend it, leaving only the Irish Parliamentary Party, whose representation at Westminster had been reduced to miniscule size at the 1918 General Election, present at the debates. James Craig's brother told the British House of Commons unambiguously that the six northeastern counties were the largest possible area that unionists could "hold".