what part of ireland is still under british rule
Northern Ireland Northern Ireland (Irish: Tuaisceart Éireann [ˈt̪ˠuəʃcəɾˠt̪ˠ ˈeːɾʲən̪ˠ] ( listen);[8] Ulster-Scots: Norlin Airlann) is a part of the United Kingdom in the north-east of the island of Ireland,[9][10] variously described as a country, province or region.[11][12][13] Northern Ireland shares a border to the south and west with the Republic of Ireland. In 2011, its population was 1,810,863,[4] constituting about 30% of the island's total population and about 3% of the UK's population. Established by the Northern Ireland Act 1998 as part of the Good Friday Agreement, the Northern Ireland Assembly holds responsibility for a range of devolved policy matters, while other areas are reserved for the British government. Northern Ireland co-operates with the Republic of Ireland in some areas, and the Agreement granted the Republic the ability to "put forward views and proposals" with "determined efforts to resolve disagreements between the two governments".[14]
History of Ireland 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 an Anglo-Irish Treaty. The Irish delegation was led by Arthur Griffith and Michael Collins. This abolished the Irish Republic and 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 independence for the 26-county Irish Free State (which renamed itself Ireland in 1937, and declared itself a republic in 1949); while the 6-county Northern Ireland, gaining Home Rule for itself, remained part of the United Kingdom. For most of the next 75 years, each territory was strongly aligned to either Catholic or Protestant ideologies, although this was more marked in the six counties of Northern Ireland.