Eochaid (or Eochu) Ailtlethan ("broad blade"), son of Ailill Caisfiaclach, was, according to medieval Irish legends and historical traditions, a

High King of Ireland High King of Ireland ( ) was a royal title in Gaelic Ireland held by those who had, or who are claimed to have had, lordship over all of Ireland. The title was held by historical kings and was later sometimes assigned anachronously or to leg ...

. According to the ''

Lebor Gabála Érenn ''Lebor Gabála Érenn'' (literally "The Book of Ireland's Taking"; Modern Irish spelling: ''Leabhar Gabhála Éireann'', known in English as ''The Book of Invasions'') is a collection of poems and prose narratives in the Irish language inten ...

'', he took the throne after overthrowing and killing the previous incumbent, Adamair. He ruled for eleven years, until he was killed in battle by Fergus Fortamail. The ''

'' synchronises his reign with that of

Ptolemy V Epiphanes Ptolemy V Epiphanes Eucharistus (, ''Ptolemaĩos Epiphanḗs Eukháristos'' "Ptolemy the Manifest, the Beneficent"; 9 October 210–September 180 BC) was the Pharaoh, King of Ptolemaic Egypt from July or August 204 BC until his death in 180 BC. ...

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

(204–181 BC). The chronology of

Geoffrey Keating Geoffrey Keating (; – ) was an Irish historian. He was born in County Tipperary, Ireland, and is buried in Tubrid Graveyard in the parish of Ballylooby-Duhill. He became a Catholic priest and a poet. Biography It was generally believed unt ...

's ''Foras Feasa ar Éirinn'' dates his reign to 285–274 BC, that of the ''

Annals of the Four Masters The ''Annals of the Kingdom of Ireland'' () or the ''Annals of the Four Masters'' () are chronicles of Middle Ages, medieval Irish history. The entries span from the Genesis flood narrative, Deluge, dated as 2,242 Anno Mundi, years after crea ...

'' (which gives him a reign of seventeen years) to 414–396 BC.''

'
M4787-4804
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References

Legendary High Kings of Ireland 3rd-century BC legendary monarchs Usurpers Monarchs killed in action Irish regicides {{Celt-myth-stub