Eoghan mac Néill (old orthography: Eóġan mac Néill) (died 465[1]) son of Niall Noígiallach, was an Irish king who founded the kingdom of Ailech, later Tír Eoghain (modern County Tyrone) in the 5th century. He was also the ancestor of the Cenél nEoghain dynasty and their septs (MacLaughlin, O'Neill, Corrigan, etc.).
Eogan was a close friend of Saint Patrick and received Patricks blessing.[2] With his brother the high king Lóegaire mac Néill (d.462), he was one of the judges in a dispute over the succession to Amalgaid (d.440), king of Connacht among his sons competing to rule their territory of Tir Amalgaidh in northwest Connacht.[3]
Eoghan, King of Tír Eoghain, and Prince of Inis Eoghain is buried at St. Patrick's Church in Iskaheen, Innishowen, Donegal. A plaque there states "Eoghan Prince of Iniseoghain, Son of Niall of the Nine Hostages. Died 465 of grief for his brother Conall. Baptised by Patrick and buried in Uisce Chaoin"
His sons included Muiredach mac Eógain, his successor in Ailech; Fergus, founder of the Cenél Fergusa; and Echach Binnich, founder of the Cenél mBinnig.
The manuscript known as the Laud 610 Genealogies (Oxford, Bodleian Library MS. Laud 610, fo. 75a 1, fifteenth century) gives seven descendant clans of the Cenél nEogain, in the Bredach.