Eterscél Mór ("the great"), Son of Eogan MacAilella, Grandson of Ailill Anglonnach MacIar, great grandson of Íar mac Dedad, a descendant of Óengus Tuirmech Temrach, of the Érainn of Munster was, according to medieval Irish legend and historical tradition, a High King of Ireland.
[1] He has no children, and it is prophesied that a woman of unknown race will bear him a son.
One night, in Eterscél's house, she is visited by an unknown man who flies in her skylight in the form of a bird, and she has his child, the future High King Conaire Mór, who is brought up as Eterscél's son.
Eterscél ruled for five or six years, at the end of which he was killed by Nuadu Necht in the battle of Aillenn.
The Lebor Gabála Érenn synchronises his reign with that of the Roman emperor Augustus (27 BC – AD 14) and the birth of Christ, and makes him contemporary with legendary provincial kings Conchobar mac Nessa, Cairbre Nia Fer, Cú Roí and Ailill mac Máta.