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.
History of Northern Ireland
Throughout this period, the main paramilitary organisations began to form. 1972 was the most violent year of the conflict. In 1970 the Provisional IRA, was created as a breakaway from what then became known as the Official IRA (the Provisionals came from various political perspectives, though most rejected the increasingly Marxist outlook of the Officials and were united in their rejection of the Official's view that physical force alone would not end partition), and a campaign of sectarian attacks by loyalist paramilitary groups like the Ulster Defence Association (formed to co-ordinate the various Loyalist vigilante groups that sprung up) and others brought Northern Ireland to the brink of civil war. On 30 March 1972, the British government, unwilling to grant the unionist Northern Ireland government more authoritarian special powers, and now convinced of its inability to restore order, pushed through emergency legislation that prorogued the Northern Ireland Parliament and introduced direct rule from London. In 1973 the British government dissolved the Parliament of Northern Ireland and its government under the Northern Ireland Constitution Act 1973.