One of the supposed twelve sons of Lóegaire mac Néill, his mother was Angias, a daughter of (Ailill) Tassach of the Uí Liatháin.
Before he was born Patrick is said by the late Vita tripartita Sancti Patricii to have cursed Lóegaire's descendants so that they would never enjoy the kingship.
[5] His apparent inactivity while the annals are full of the doings of his kinsmen Coirpre mac Néill and of Muirchertach Macc Ercae is a puzzle.
[4] According to the Vita tripartita, Lugaid was killed by a bolt from the heavens when he mocked Patrick at a place later called Achad Forchai.
Allowing that the association with Saint Patrick is not original, it is thought that this account preserves a memory of some tale involving Lugaid's death by lightning, making him one of several early Irish kings, among whom his father, who were perhaps believed to have died by supernatural means.