Efficient family research requires an understanding of the historical events that affected your ancestors and the records about them. Learning about wars, laws, migrations, settlement patterns, local events, and economic or religious trends may help you understand family movements. These events may also direct you to records, such as settlement certificates or military records, that mention your family. Learning about the conditions in which your ancestors lived and the events that influenced their lives will also help you understand your ancestors as human beings.

Events in Irish history that may have influenced your ancestors and the records about them include the following:

1002-14	Irish Kingdom. Brian Boru united Irish regional kings.
1200-50	British colonizing. English colonists were sent to colonize Ireland.
1494	The English crown officially claimed Ireland as part of England. Meetings and legislative drafts of the Irish parliament were subject to the control of the English king and council. But in 1496 Kildare, the lord deputy who had ruled Ireland before 1494, was reinstated.
1549-1640	Plantations. Many English and Scottish families were sent to Ireland to receive estates as rewards from the king. Lands were mainly granted in the counties of Leix, Offaly, Tipperary, Wexford, Leitrim, and Longford and in the major plantations in Ulster province. Some civil servants received lands in Munster province. Many Irish families were displaced.
1603	Scots began settling Ulster province.
1641-52	Irish Rebellion. Ulster natives overthrew English colonial rule, and Irish rebels established a Catholic government called the Confederation of Kilkenny.
1649	Oliver Cromwell crushed the rebellion in Ireland and awarded lands to Protestants. Catholics who could prove they had not been involved in the rebellion were given estates in West Clare. Some prisoners were sent to New England.
1690	The Irish Parliament was established in Dublin.
1720	British Parliament began to legislate for Ireland, and the British House of Lords had the powers of a supreme court in Irish law cases.
1782-93	Legislative acts gave power back to the Irish Parliament and more rights to Irish Roman Catholics.
1800	Ireland united with England and Scotland to form the United Kingdom of Great Britain and Ireland.
1821	The first genealogically useful census was taken.
1845	Civil registration of non-Catholic marriages began.
1845-49	Potato Famine. Blight destroyed the potato crop for several consecutive years resulting in starvation and disease. Millions died and millions emigrated.
1850-1914	Many Irish emigrated, which helped to stabilize the economy.
1850	The Reform Act was passed, basing the right to vote on occupation rather than on property ownership.
1858	The Principle Probate Registry began proving Irish probates.
1864	Civil registration of births and deaths began. Marriage registration began to include Catholics.
1869	The Church of Ireland ceased to be recognized as the state church.
1919-22	Civil strife resulted in 1,468 deaths. A treaty, signed on 7 January 1922, split Ireland into the predominantly Catholic Republic of Ireland and the predominantly Protestant Northern Ireland.
1922	Irish Civil War. Irregulars of the Irish Republican Army opposed to the 1922 treaty occupied the Four Courts building where many Irish records were housed. The building was burned and many records destroyed.