Throughout the early medieval period Irish missionaries preached the gospel and established new monastic communities across the continent of Europe. This first great outward movement in Christian times was halted by the upheavals arising from the Viking impact on Ireland. Much later, with the overthrow of the Gaelic political order by the English in the 17th century, the first major migration of the modern period began.
The social and political disadvantages encountered by the Catholic nobility and gentry encouraged many of them to emigrate to Europe. This exodus reached its peak in the 18th century when Irish soldiers and statesmen earned distinction in the service of many European armies, those of France, Spain and Austria in particular. Thousands of Irishmen, known as the "Wild Geese", whose ranks included names like MacMahon, Taaffe, O'Neill and Butler, died fighting for continental armies up to the time of the Napoleonic wars.
In modern times involvement in the life of continental Europe has been mainly cultural. Joyce and Beckett both deliberately chose the continent as their base. Since acceding to the European Community in 1973 new opportunities to live and work in continental Europe have been created. Increasing numbers of young Irish men and women can now be found in the main EU countries, and this tendency is likely to grow.
It is estimated that there may be up to one million people of Irish birth (including those from Northern Ireland) in Britain today. However, there would be many more second or even third generation Irish, though precise figures are lacking. Many of these are conscious of their heritage, and interested in promoting Irish cultural and sporting activities, as could be seen in their contribution to the successes of the Republic of Ireland soccer team.
In the early 19th century increasing numbers went to the United States and Canada. The Great Famine hugely accelerated emigration and approximately five million people emigrated in the course of the century. Although the Irish settled all over the United States, they acquired exceptional political influence in cities like Boston, New York, Philadelphia, Chicago and San Francisco. Their highly developed political and organisational skills enabled them achieve control of city administrations and leave a notable mark on the American political style.
Recent statistics indicate that over 40 million persons in the United States claim some Irish ancestry, and that 25% of this figure claim solely Irish ancestry. The States with the largest numbers of Irish-Americans are California, New York and Pennsylvania, in that order. Irish-Americans are found in all areas of political, public, professional and economic life. Complete integration in American society has not, however, lost all these descendants to the culture and aspirations of Ireland and the maintenance of personal and family links is a continuing aspect of the relationship between the Irish and Irish-American communities.
Many distinguished American politicians are of Irish descent. Recent US Presidents of Irish ancestry included John F. Kennedy, Richard M. Nixon and Ronald Reagan.Irish immigrants began to arrive in Canada in significant numbers in the 18th and early 19th centuries. By 1867 people of Irish descent comprised over 20% of the Canadian population, being outnumbered only by British and French-Canadians. Many leading figures in Canadian political life in the 19th century were either Irish-born or of Irish descent, including the distinguished statesman Thomas D'Arcy McGee (d. 1868). More recently, Brian Mulroney has been Prime Minister of Canada.
The Irish have made a significant contribution to the development of Australia and of the Australian identity from the time of the first European settlement there in 1788. Up to 30% of the Australian population is estimated to be of Irish descent, making Australia probably the most 'Irish' country in the world outside of Ireland itself.
In the early years many of those arriving came as convicts, both political and non-political. After the Great Famine increasing numbers of free settlers came, especially from Munster, settling mainly in New South Wales, Victoria and Queensland. These people and their descendants have left a rich legacy in every walk of Australian life, most notably in politics, the trade unions, the churches, education, literature, law, medicine and sport. Their powerful influence on Australian politics is exemplified by the fact that six of the seven Prime Ministers of Australia in the period 1929-49 had Irish forebears. More recently, Prime Minister Paul Keating, who took office in 1991, has relatives in Co. Galway.
In sport, Australian Rules football, the most popular spectator sport in the country, is widely acknowledged as having its origins in Gaelic football. The two codes are so similar that an official international series between Ireland and Australia was inaugurated in 1984 under composite rules.
The Irish presence in New Zealand and their contribution to that country's development has also been considerable. It is estimated that 15% of the total population is of Irish descent. The Irish have played a prominent role in many aspects of New Zealand life. The first premier, John Edward Fitzgerald, was Irish-born. Captain Hobson, who signed the Treaty of Waitangi which founded the modern state of New Zealand, came from Waterford.
In the early years of the 19th century, with the end of the wars in Europe, many Irish soldiers went to serve in the armies of the South American republics. At the same time Irish people went to work and farm in South America, especially in Argentina; a high proportion of these came from the Midlands. William Brown, born in Co. Mayo in 1777, arrived in Buenos Aires in 1812 and went on to found the Argentinean navy. Earlier, the Co. Offaly-born Don Ambrosio Higgins served as Spanish viceroy of Peru in the 1700s; his son Bernardo O'Higgins helped secure the independence of Chile and was its first head of government, from 1818 to 1823.
Irishmen also played a notable part in the history of Mexico. In Mexico City today a memorial recalls the Irishmen of the St. Patrick's Battalion who died in the Mexican-American war of 1847.
Ireland has had the highest rate of emigration of any European country for the past two centuries, taking one decade with another. Unusually in the context of European emigration, as many women as men have emigrated. This enabled Irish people to intermarry to a great extent, and thus sustain a lively sense of community abroad. Ireland has also had an exceptionally low rate of return migration. This may now be changing with the growth in the number of educated emigrants during the 1980s. Many of these have gone abroad to gain experience, with the intention of returning if suitable employment opportunities arise. Improved communications also allow for the maintenance of closer and more sustained contact with home