[1] He was the foster-son of Cimbáeth and Macha Mong Ruad and he took power by killing his predecessor (and his foster-mother's killer), Rechtaid Rígderg.
[3] This partitioning of the island stood for three hundred years, until the establishment of the provinces under Eochu Feidlech.
The reign of Úgaine Mór was thirty or forty years, until he was killed by his brother Bodbchad.
The Lebor Gabála synchronises Úgaine Mór's reign to that of Ptolemy II Philadelphus (281–246 BCE).
Annals of the Kingdom of Ireland by John O'Donovan lists twenty-five children (twenty-two sons and three daughters), but does not list another apparent child of Úgaine Mór, a daughter called "Lathar" (not to be confused with Latharn).