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
3rd century
Year
Date
Event
c. 220 AD
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]
4th century
Year
Date
Event
c. 300 AD
Pollen data records from the late Iron Age indicate a resurgence in human activity after a relatively stagnant period[10]
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.
15th century
Year
Date
Event
1472
The Annals of the Four Masters records that the King of England sent an exotic animal (possibly a giraffe) to Ireland.[24]
1490
An earthquake takes place at Sliabh Gamh in County Mayo.[25]
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.
Battle of Aughrim; One of the bloodiest fought in Ireland with up to 7,000 people killed
1695
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]