Budget Travel Northern Ireland Sources of budget travel northern ireland resources from the Web

The state was neutral during World War II but offered some assistance to the Allies. In 1949 the state was declared to be a republic; since that time it has been commonly referred to as the "Republic of Ireland". The state was plagued by poverty and emigration until the 1990s. That decade saw the beginning of unprecedented economic success, in a phenomenon known as the "Celtic Tiger". By the early 2000s, it had become one of the richest countries (in terms of GDP per capita) in the European Union, moving from being a net recipient to a net contributor and from a population with net emigration to one with net immigration.

In a number of areas, the island operates officially as a single entity, for example, in sport. The major religions, the Roman Catholic Church, the Church of Ireland and the Presbyterian Church of Ireland, are organised on an all-island basis. 92% of the population of the Republic of Ireland are Roman Catholic, and 40% in Northern Ireland. Some trades unions are also organised on an all-Irish basis and associated with the Irish Congress of Trades Unions (ICTU) in Dublin, while others in Northern Ireland are affiliated with the Trades Union Congress (TUC) in the United Kingdom. The island also has a shared culture across the divide in many other ways. Traditional Irish music, for example, though showing some variance in all geographical areas, is broadly speaking the same on both sides of the border. Irish and Scottish traditional music are similar.

The late nineteenth and early twentieth centuries saw a vigorous but unsuccessful campaign for Irish home rule, followed by the eclipse of moderate nationalism by militant separatism. In 1922, following the Anglo-Irish War, the twenty-six counties of Ireland seceded from the United Kingdom as the Irish Free State. The remaining six, in the north-east, remained within the Union as Northern Ireland. Secession for southern Ireland led directly to the Civil War, as militant nationalists split into two factions and turned against one another.

The area now known as Northern Ireland has had a diverse history. From serving as the bedrock of Irish resistance in the era of the plantations of Queen Elizabeth and James I in other parts of Ireland, it became itself the subject of major planting of Scottish and English settlers after the Flight of the Earls in 1607 (when the native aristocracy left en masse).

The all-island Kingdom of Ireland (1541-1801) was incorporated into the United Kingdom in 1801 under the terms of the Act of Union, under which the kingdoms of Ireland and Great Britain merged under a central parliament, government and monarchy based in London. In the early 20th century Unionists, led by Sir Edward Carson, opposed the introduction of Home Rule in Ireland. Unionists were in a minority on the island of Ireland as a whole, but formed a majority in the northern province of Ulster. Therefore, after the First World War, Ireland was partitioned in 1921 under the terms of the Government of Ireland Act 1920 between six of the nine Ulster counties in the northeast (forming Northern Ieland) and the remaining twenty-six counties of the south and west (forming Southern Ireland and became the Irish Free State in 1922). When the latter achieved dominion status, the six Northern Ireland counties — under the procedures laid out in the Anglo-Irish Treaty, 1921 — opted out, and so remain as part of the United Kingdom.