Republic of Ireland (Poblacht na hÉireann), is a sovereign state in north-western Europe occupying about five-sixths of the island of Ireland. The capital and largest city is Dublin, located in the eastern part of the island, whose metropolitan area is home to around a third of the country's 4.6 million inhabitants. The state shares its only land border with Northern Ireland, a part of the United Kingdom. It is otherwise surrounded by the Atlantic Ocean, with the Celtic Sea to the south, Saint George's Channel to the south-east and the Irish Sea to the east. It is a unitary,parliamentary republic. The Oireachtas (legislature) consists of a lower house, Dáil Éireann (House of Representatives, lit. 'Assembly of Ireland'), an upper house, Seanad Éireann (Senate of Ireland), and an elected President (Uachtarán) who serves as the largely ceremonial head of state, but with some important powers and duties. The head of government is the Taoiseach (Prime Minister, literally 'Chief', a title not used in English), who is elected by the Dáil and appointed by the President, and appoints other government ministers.
The Irish Free State was created in 1922 as a result of the Anglo-Irish Treaty. It effectively became a republic, with an elected president, under the constitution of 1937, in which it was named "Ireland". It was officially declared a republic in 1949. Ireland became a member of the United Nations in December 1955. It joined the European Economic Community (EEC), predecessor of the European Union, in 1973. The state had no formal relations with Northern Ireland for most of the twentieth century, but during the 1980s and 1990s the British and Irish governments worked with the Northern Ireland parties towards a resolution to "the Troubles". Since the signing of the Good Friday Agreement in 1998, the Irish government and Northern Ireland executive have co-operated on a number of policy areas under the North-South Ministerial Council created by the Agreement.
Ireland ranks among the wealthiest countries in the world in terms of GDP per capita. After joining the EEC, Ireland enacted a series of liberal economic policies that resulted in rapid economic growth. The country achieved considerable prosperity from 1995 to 2007, during which it became known as the Celtic Tiger. This was halted by an unprecedented financial crisis that began in 2008, in conjunction with the concurrent global economic crash.
In 2011 and 2013 Ireland was ranked as the seventh-most developed country in the world by the United Nations Human Development Index. It also performs well in several metrics of national performance, including freedom of the press, economic freedom and civil liberties. Ireland is a member of the European Union and is a founding member of the Council of Europe and theOECD. The Irish government has followed a policy of neutrality through non-alignment since immediately prior to World War 2 and the country is consequently not a member of NATO, although it does participate in Partnership for Peace.