Republic of Ireland–United Kingdom border
Originally intended as an internal boundary within the United Kingdom of Great Britain and Ireland, the border was created in 1921 under the United Kingdom Parliament's Government of Ireland Act 1920. Prior to this, a separatist Irish parliament had been established in Dublin, which did not recognise the Government of Ireland Act, and was actively engaged in the Irish War of Independence. The Act was intended to deliver Home Rule in Ireland, with separate parliaments for Southern Ireland (which included three of the nine counties of Ulster) and Northern Ireland. Six of the thirty-two counties of Ireland were assigned to Northern Ireland, and the rest of Ireland comprising 26 counties to Southern Ireland.
Partition of Ireland
If the Houses of Parliament of Northern Ireland had not made such a declaration, under Article 14 of the Treaty, Northern Ireland, its Parliament and government would have continued in being but the Oireachtas would have had jurisdiction to legislate for Northern Ireland in matters not delegated to Northern Ireland under the Government of Ireland Act. This never came to pass. On 13 December 1922, Craig addressed the Parliament of Northern Ireland, informing them that the King had responded to the Parliament's address as follows: