The Irish people (Irish: Muintir na hÉireann, na hÉireannaigh, na Gaedhil) are an ethnic group who originate in Ireland, an island in northwestern Europe. Ireland has been populated for around 9,000 years (according to archaeological studies, see Prehistoric Ireland), with the Irish people's earliest ancestors recorded have legends of being descended from groups such as the Nemedians, Fomorians, Fir Bolgs, Tuatha Dé Danann and the Milesians the last group supposedly representing the "pure" Gaelic ancestry, and still serving as a term for the Irish race today. The main groups that interacted with the Irish in the Middle Ages include the Scottish people and the Vikings, with the Icelanders especially having some Irish descent. The Anglo-Norman invasion of the High Middle Ages, the English plantations and the subsequent English rule of the country introduced the Normans and Flemish into Ireland. Welsh, Picts, Bretons, and small parties of Gauls and even Anglo-Saxons are known in Ireland from much earlier times.
There have been many notable Irish people throughout history. The 6th century Irish monk and missionary Columbanus is regarded as one of the "fathers of Europe", followed by Kilian of Würzburg and Vergilius of Salzburg. The scientist Robert Boyle is considered the "father of chemistry". Famous Irish explorers include Brendan the Navigator, Ernest Shackleton, and Tom Crean. By some accounts, the first European child born in North America had Irish descent on both sides; while an Irishman was also the first European to set foot on American soil in Columbus' expedition of 1492.
Until the end of the early modern period, the majority of educated Irish were proficient at both speaking and writing in Latin and Greek. Notable Irish writers in the English language include Bram Stoker, Jonathan Swift, James Joyce, Flann O'Brien, Oscar Wilde, William Butler Yeats, Samuel Beckett, Patrick Kavanagh and Seamus Heaney. Some of the 20th century writers in the Irish language include Brian O'Nolan (aka Flann O'Brien), Máirtín Ó Cadhain, Pádraic Ó Conaire, Tomás Ó Criomhthain, Peig Sayers, Muiris Ó Súilleabháin and Máirtín Ó Direáin.
Large populations of people of Irish ethnicity live in many western countries, particularly in English-speaking countries. Historically, emigration has been caused by politics, famine and economic issues. An estimated 80 million people make up the Irish diaspora today, which includes Great Britain, the United States, Australia, Canada, Argentina, Chile, South Africa, New Zealand, Mexico, France, Germany and Brazil. The largest number of people of Irish descent live in the United States—about ten times more than in Ireland itself.