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Brief history of Ireland

Ireland’s history is marked by invasions and settlement by foreign peoples. The Celts, the Vikings, the Normans, the English and the Scots have all left their mark on Irish history, geography, culture, language and people.

Prehistoric Ireland

The earliest settlers were hunter-gatherers who arrived around 8000 BC during the Mesolithic era.  Impressive megalithic tombs built in the fourth millennium BC are dotted around the Irish countryside, most notably that at Newgrange, whose central room is aligned with the rising sun on the day of the winter solstice.

Celtic tribes reached Ireland around the 6th century BC. The Irish language is a member of the Celtic language family, and Irish art and culture were also heavily influenced by the Celts.

Christian Ireland

Glendalough St Patrick, the patron saint of Ireland, introduced Christianity to Ireland in the 5th century.
Ireland in the early Christian era was an agrarian society and, in the absence of large towns or cities, large monasteries played a major role in Irish social and political life.  Some of these can still be seen today, such as Glendalough in County Wicklow, and Clonmacnoise in County Offaly.

The rise of the Irish monasteries also brought with it a golden age of Irish art and crafts, most notably in metalwork and the production of illuminated manuscripts, such as the world-renowned Book of Kells now housed in Trinity College in Dublin, and the Tara Brooch, now in the National Museum in Dublin

The Vikings

From 795 AD Ireland was under regular attack by Viking raiders who targeted the rich monasteries and caused their eventual decline.  Raiding in the ninth century was followed by settlement.  The Vikings founded trade outposts in Ireland which later developed into major towns and cities such as Dublin, Cork, Limerick and Waterford.  

The Norman Invasion

Norman mercenaries invaded Ireland from England in 1169 at the request of an ousted Irish king hoping to regain his territory, and were followed by an invasion by King Henry II of England in 1171 to assert control over his Norman subjects, with the King declaring himself Lord of Ireland.  The Normans had a profound impact on the island, but many eventually assimilated into Irish culture, learning to speak the native language and marrying into Irish families.  By the end of the 15th century English rule in Ireland was effectively limited to a small enclave around Dublin known as the Pale.

Early Modern Ireland

The Tudor monarchs of England sought to regain control of Ireland in the 16th century.  Henry VIII declared himself King of Ireland and he and his successors established English settlements and fought a series of military campaigns, as well as making strenuous efforts to impose Protestantism on Catholics.  The conquest of Ireland was effectively complete in 1601 following the Battle of Kinsale. 

An Irish rebellion during the English Civil War was crushed by Oliver Cromwell between 1649 and 1652 with great loss of life.  Large tracts of fertile land owned by Catholics were confiscated and redistributed among Cromwell's soldiers and Scottish colonists, displacing many families, and leaving a legacy of bitterness that has endured for centuries.

Penal laws against Catholics were introduced throughout the seventeenth century, excluding them from holding public office, entering professions, teaching, owning firearms, restricting their ownership of property and inheritance of land and outlawing Catholic clergy, while at the same time forcing Catholics to pay tithes to Protestant clergy.

Modern Ireland

Tension between the British rulers and the Irish population continued. Following a rebellion in 1798, the Irish Parliament was abolished and Ireland formally became part of the United Kingdom.  A campaign for emancipation of Catholics succeeded in removing many restrictions on Catholics in 1829.

The Great Famine (1845-52) followed potato blight which destroyed the staple food of the poor. Exacerbated by the laissez-faire economic policies of the British government, it led to the death by starvation and disease of a million people and the emigration of a million more, out of a population of about eight million.  The island’s population fell by a quarter, and high emigration continued in succeeding decades with huge demographic effects: Ireland’s population is roughly the same now as in the 1870s. Use of the Irish language declined catastrophically.  

Ongoing discontent with British rule led to repeated rebellions and agitation for land reform and home rule in the later 19th century.

Towards an Irish StateProclamation

In 1914 the British Parliament passed a Home Rule Bill intended to grant the right to self-government to Ireland, but it was postponed due to the outbreak of the World War I.  On Easter Sunday, 23rd April 1916, the Irish Volunteers and the Irish Citizen Army staged an armed rebellion in Dublin, and proclaimed Ireland's independence.   The Easter Rebellion was defeated after several days of fighting.  While the rebellion was initially opposed by the mass of the population, the execution of several of its leaders, including Patrick Pearse and James Connolly, alienated Irish public opinion against British rule.

At the 1918 election the pro-independence Sinn Féin party won a landslide victory and instead of taking up their seats in British Parliament set up the first Dáil, an independent parliament in Dublin, led by Eamon de Valera (who became Taoiseach and later, President of Ireland). The subsequent War of Independence (1919-1921) ended with the signing of the Anglo-Irish Treaty in December 1921, which divided the country into the independent Irish Free State (26 counties) and six counties in Ulster which remained within the United Kingdom, known as Northern Ireland. A civil war (1921-23) followed between the newgovernment and those opposed to the Treaty, who felt it did not provide full independence.  The civil war shaped and determined political allegiances for decades: the two largest political parties in Ireland are descended from pro-Treaty (Fine Gael) and anti-Treaty (Fianna Fáil) parties. 


Bunreacht na hEireann‌Bunreacht na hÉireann, the second Irish Constitution, was enacted by the people in 1937. The Irish Free State became a Republic in 1949, severing the final links to the British monarchy.

Ireland was neutral during the Second World War, although large numbers of Irish citizens fought in Allied forces.  Ireland joined the UN in 1955 and became a member of the now European Union in 1973.  

You can find more information on Northern Ireland, and on more recent developments in the relationship between Ireland and Britain, here.