Celtic tribes arrived on the island between 600 and 150 B.C. Invasions by Norsemen that began in the late 8th century were finally ended when King Brian BORU defeated the Danes in 1014. Norman invasions began in the 12th century and set off more than seven centuries of Anglo-Irish struggle marked by fierce rebellions and harsh repressions. The Irish famine of the mid-19th century saw the population of the island drop by one third through starvation and emigration. For more than a century after that the population of the island continued to fall only to begin growing again in the 1960s. Over the last 50 years, Ireland's high birthrate has made it demographically one of the youngest populations in the EU. The modern Irish state traces its origins to the failed 1916 Easter Monday Uprising that touched off several years of guerrilla warfare resulting in independence from the UK in 1921 for 26 southern counties; six northern (Ulster) counties remained part of the UK. Unresolved issues in Northern Ireland erupted into years of violence known as the "Troubles" that began in the 1960s. The Government of Ireland was part of a process along with the UK and US Governments that helped broker what is known as The Good Friday Agreement in Northern Ireland in 1998. This initiated a new phase of cooperation between the Irish and British Governments. Ireland was neutral in World War II and continues its policy of military neutrality. Ireland joined the European Community in 1973 and the euro-zone currency union in 1999. The economic boom years of the Celtic Tiger (1995-2007) saw rapid economic growth, which came to an abrupt end in 2008 with the meltdown of the Irish banking system. Today the economy is recovering, fueled by large and growing foreign direct investment, especially from US multi-nationals.
Ireland is a small, modern, trade-dependent economy. Ireland was among the initial group of 12 EU nations that began circulating the euro on 1 January 2002. GDP growth averaged 6% in 1995-2007, but economic activity dropped sharply during the world financial crisis and the subsequent collapse of its domestic property market and construction industry. Faced with sharply reduced revenues and a burgeoning budget deficit from efforts to stabilize its fragile banking sector, the Irish Government introduced the first in a series of draconian budgets in 2009. These measures were not sufficient to stabilize Ireland’s public finances. In 2010, the budget deficit reached 32.4% of GDP - the world's largest deficit, as a percentage of GDP. In late 2010, the former COWEN government agreed to a $92 billion loan package from the EU and IMF to help Dublin recapitalize Ireland’s banking sector and avoid defaulting on its sovereign debt. In March 2011, the KENNY government intensified austerity measures to meet the deficit targets under Ireland's EU-IMF bailout program.In late 2013, Ireland formally exited its EU-IMF bailout program, benefiting from its strict adherence to deficit-reduction targets and success in refinancing a large amount of banking-related debt. In 2014, the economy rapidly picked up and GDP grew by 5.2%. The recovering economy assisted lowering the deficit to 2.5% of GDP. In late 2014, the government introduced a fiscally neutral budget, marking the end of the austerity program. Continued growth of tax receipts has allowed the government to lower some taxes and increase public spending while keeping to its deficit-reduction targets. In 2015, GDP growth exceeded 26%, the highest growth in the EU for two consecutive years. This dramatic increase reflected one-off statistical revisions, multinational corporate restructurings, and the aircraft leasing sector, rather than gains in the on the ground economy. Growth moderated to around 4.2% in 2016.In the wake of the collapse of the construction sector and the downturn in consumer spending and business investment, the export sector, dominated by foreign multinationals, has become an even more important component of Ireland's economy. Ireland’s low corporation tax of 12.5% and a talented pool of high-tech laborers have been key factors in encouraging business investment. Loose tax residency requirements made Ireland a common destination for international firms seeking to avoid taxation. In 2014, amid growing international pressure, the government announced it would phase in more stringent tax laws, effectively closing a commonly used loophole.