Mesolithic hunter-gatherers occupy sites such as that at Mount Sandel in Ulster
c. 4000 BC
Agriculture (including the keeping of livestock, and crop farming) has its beginnings in Ireland, at sites such as the Céide Fields in Connacht
c. 3500 BC
The Neolithic peoples of the Boyne Valley build a complex of chamber tombs, standing stones and enclosures over a period of hundreds of years. (Newgrange itself is dated to 3300–2900 BC).
Ptolemy's Geographia provides the earliest known written reference to habitation in the Dublin area, referring to a settlement in the area as Eblana Civitas
The Annals of the Four Masters, Foras Feasa ar Éirinn, and other semi-historical (non-contemporary) texts, place Cormac mac Airt as a longstanding High King of Ireland.[6][7] (The Annals date his reign as 226–266, but scholars vary in their assessment of Mac Airt's reign as legend or historical fact)[8][9]
Máel Sechnaill demands (and is paid) "tribute" by the Vikings at Dublin (this tribute date is sometimes recognised as the "foundation date" of Dublin as a city)
Gerald FitzGerald, 3rd Earl of Desmond, mysteriously disappears; Gearóid Íarla is forever afterwards judged to be sleeping in a cave under Lough Gur, waiting to gallop out on his silver-shod horse and rescue Ireland at the moment of greatest need.
The Annals of the Four Masters records a drought, in which no rain fell "from Bealtaine to Lammas" (1 May to 1 August), resulting in disease and plague.
1577
November
The Annals of the Four Masters records that the Great Comet of 1577 "was wondered at by all universally".
The Supreme Council of the Irish Catholic Confederation signs an agreement with a representative of Charles I, which procures some rights for Catholics in return for their military support of the royalists in England.
The members of the Supreme Council are arrested; the General Assembly renounces the agreement with England.
1647
A more favorable agreement is reached with Charles's representative, which promises toleration of Catholicism, a repeal of Poynings' Law, and recognition of lands taken by Irish Catholics during the war.
The Education Act, one of a series of Penal Laws, is passed in 1695. It prohibits Catholics from sending their children to be educated abroad, and remains in place until 1782.
Tithe War: A force of one hundred and twenty armed police forcibly takes possession of cattle belonging to a Roman Catholic priest, in lieu of his compulsory tithe to the AnglicanChurch of Ireland.
Tithe War: The passage of the Tithe Commutation Act 1836 reduces the amount of the church's tithe and changes the manner of payment, which largely ends the unrest.
1845–1849
Great Irish Famine: A potato blight destroys two-thirds of Ireland's staple crop, leading to an estimated 1 million deaths and emigration of a further 1 million people.[27]
^O'Brian, William (2005). Ross Island: Mining, Metal and Society in Early Ireland. Oxbow books. ISBN978-0-9535620-3-9.
^Johnston, Wesley; Abbot, Patrick. "Celtic Ireland in the Iron Age". History of Ireland. WesleyJohnston.com. Archived from the original on 12 November 2012. Retrieved 17 November 2012.
^Moody, T.W; Martin, F.X; Byrne, F.J, eds. (1982). A New History of Ireland VIII: A Chronology of Irish History to 1976 - A Companion to Irish History Part I. Oxford Clarendon Press. ISBN978-0-19-821744-2.
^Annals. Annals of Ulster and Annals of the Four Masters. Palladius, having been consecrated by Celestine, bishop of the city of Rome, is sent to Ireland [...] in the eighth year of Theodosius.
^Annals of Ulster - U432. Annals of Ulster. Archived from the original on October 21, 2012. Retrieved November 17, 2012. Year U432: Patrick arrived in Ireland in the ninth year of the reign of Theodosius the Less and in the first year of the episcopate of Xistus, 42nd bishop of the Roman Church. So Bede, Maxcellinus and Isidore compute in their chronicles.
^Ó Corráin, Donnchadh (1972). Ireland Before the Normans. The Gill history of Ireland. Gill and MacMillan.
^Wikisource - Treaty of Windsor – via Wikisource. Text reads: This is the agreement which was made at Windsor in the octaves of Michaelmas [October 6] in the year of Our Lord 1175
^Annals of the Four Masters – Part 9. Annals of the Four Masters. Archived from the original on October 21, 2012. Retrieved November 17, 2012. Great heat and drought prevailed in this Summer, so that people crossed the beds of the principal rivers of Ireland with dry feet. The reaping of the corn crops of Ireland was going on twenty days before Lammas 1 August, and the trees were scorched by the heat of the sun.
^Moody, TW; Martin, FX, eds. (1967). The Course of Irish History. Cork, Ireland: The Mercier Press. p. 370.
^Annals of the Four Masters - Part 10. Annals of the Four Masters. Archived from the original on October 21, 2012. Retrieved November 17, 2012. A wonderful animal was sent to Ireland by the King of England. She resembled a mare, and was of a yellow colour, with the hoofs, of a cow, a long neck, a very large head, a large tail, which was ugly and scant of hair. She had a saddle of her own. Wheat and salt were her usual food. She used to draw the largest sled-burden by her tail. She used to kneel when passing under any doorway, however high, and also to let her rider mount.
^Annals of the Four Masters - Part 12. Annals of the Four Masters. Archived from the original on October 15, 2012. Retrieved November 17, 2012. There was an earthquake at Sliabh Gamh, by which a hundred persons were destroyed, among whom was the son of Manus Crossagh O'Hara. Many horses and cows were also killed by it, and much putrid fish was thrown up; and a lake, in which fish is now caught, sprang up in the place.
^Annals of the Four Masters - Part 13. Annals of the Four Masters. Archived from the original on October 15, 2012. Retrieved November 17, 2012. Great famine prevailed through all Ireland in this and the following year, so that people ate of food unbecoming to mention, and never before heard of as having been introduced on human dishes.