The Home Rule Crisis was a political and military crisis in the United Kingdom of Great Britain and Ireland that followed the introduction of the Third Home Rule Bill in the House of Commons of the United Kingdom in 1912.
Ulster unionists, determined to prevent any measure of home rule for Ireland, formed a paramilitary force, the Ulster Volunteers, which threatened to resist by physical force the implementation of the Act and the authority of any Dublin Parliament by force of arms. Irish nationalists responded by setting up the Irish Volunteers "to secure the rights and liberties common to all the people of Ireland". Both sides then began importing weapons and ammunition from Germany, in the Larne gun-running and Howth gun-running incidents. The UK government's ability to face down unionist defiance was thrown into question by the "Curragh incident", when dozens of British Army officers tendered their resignation rather than secure arms against Ulster loyalist seizure, forcing a climb-down by the government. The crisis was temporarily averted by the outbreak of World War I. The Home Rule Bill was enacted, but its implementation was suspended for the duration of the war.