5th to 6th centuries BC
Arrival of first Celtic invaders from central Europe. Celts soon came to dominate Ireland and earlier settlers. Christianity introduced to Ireland; traditionally associated with St Patrick, although there were some Christians in Ireland before the start of his ministry in about 432.

6th to 9th centuries
"Golden Age" of Irish history, characterised by rich cultural achievements at home, notably in the decorative arts and manuscript illumination, and by successful Christian missionary activity abroad.

800-999
Viking invasions of southern Ireland; development of overseas trade and foundation of Dublin, Cork, Limerick, and Waterford.

1002
Brian Boru, King of Munster; recognised as King of All Ireland, following his defeat of Vikings in 999; although Viking interference continued until their defeat in the Battle of Clontarf, 101s4, in which Boru was killed. 

1167-1169
Arrival of the Normans, initially at invitation of Diarmait Mac Murchada, King of Leinster, to support his ambition to become King of All Ireland. 

1172
Henry II, King of England, recognised as overlord of Ireland by both Irish and Norman aristocracy in Ireland; start of English political involvement in Ireland. 

12th to 14th centuries
Normans quickly came to control three-quarters of the land, ultimately assimilating with the local population. During this period similar parliamentary, legal, and administrative systems to those in England were being developed. 

1366
Statute of Kilkenny passed by Anglo-Irish parliament in Dublin in an (ultimately ineffective) attempt to re-establish English dominance; excommunication and heavy penalties decreed for all those following customs of or allying themselves with native Irish. 

1450
The area of effective English rule in Ireland had been reduced to an enclave around Dublin known as the Pale.

1492
Henry VII sent Sir Edward Poynings to regain control of Ireland. "Poynings Law" passed two years later, making the Irish parliament subservient to the English monarch.

1541
Henry VIII declared himself King of Ireland, the first English monarch to do so. Land declared ultimately property of Crown, to be re-granted with monarch's permission. 

1553
King's and Queen's counties (present-day Offaly and Laois) established as first settler plantations. 

1594
Start of Nine Years' War, rebellion against English rule led by Hugh O'Neill. 

1601
Formal surrender of O'Neill, following defeat at Battle of Kinsale in 1601; overthrow of native political system as country brought under English central government. 

1607
The northern counties of Ulster were confiscated to the Crown following the fleeing to Rome of Ulster chieftains. Two years later the Ulster Plantation implemented, settled by Protestant Lowland Scots and English. 

1649
Siege of Drogheda. English Parliamentary forces, led by Oliver Cromwell, defeated pro-Royalist and Roman Catholic Irish forces; many Irish landowners were exiled to Connaught and their land confiscated. 

1689
All of Ireland except Ulster rallied to support James II in his efforts to retake the English throne following the Glorious Revolution of 1688; initial military success caused Protestant settlers to flee to Enniskillen and Derry.

1690
William of Orange defeated Irish forces at the Battle of the Boyne.

1695
First Penal Laws, prevented return of land to Catholics agreed by William III at the Treaty of Limerick (1691), and successively prohibited Catholics from attending Mass, and from buying or inheriting land. The export to England of milk, butter, and cheese, and export to anywhere of Irish woollen products was also banned and the Irish economy went into decline. 

1704
Penal Code introduced denying Catholics the vote and barring them from the military. 

1778
Irish parliament passed the Relief Acts, removing some of the most oppressive disabilities of the Penal Laws.

1782
Poynings Law revoked, giving Ireland legislative independence.

1795
Orange Order founded.

1798
Uprising of United Irishmen, led by Wolfe Tone, suppressed by British troops.