Ailill Finn, son of Art mac Lugdach, was, according to medieval Irish legend and historical tradition, a High King of Ireland. In the Lebor Gabála ÃÂrenn, he succeeded to the throne when his father was killed by FÃÂachu Tolgrach and his son Dui Ladrach. He ruled for nine years. Two years into his reign, FÃÂachu Tolgrach was killed in battle against Airgetmar, son of SÃÂrlám. The men of Munster, led by Ailill's son Eochu and Lugaid, son of Eochu FÃÂadmuine, then drove Airgetmar into exile overseas. After seven years Airgetmar returned to Ireland and killed Ailill with the help of Dui Ladrach and his son FÃÂachu, but was unable to seize the throne, which was taken by Eochu.
However, in Geoffrey Keating's Foras Feasa ar ÃÂirinn and the Annals of the Four Masters FÃÂachu Tolgrach succeeded to the throne after killing Art, and is later killed by Ailill, who then took the throne, and ruled for nine or eleven years, before being killed by Airgetmar and succeeded by Eochu.
The Lebor Gabála synchronises his reign with that of Artaxerxes II of Persia (404âÂÂ358). The chronology of Keating's Foras Feasa ar ÃÂirinn dates his reign to 586âÂÂ577 BC, that of the Annals of the Four Masters to 795âÂÂ786 BC.
He is given as an ancestor of the Gamarad of Nephin, County Mayo.