Óengus mac Mugróin (died 803) was a king of the Uí Failge, a Laigin people of County Offaly. He was the son of Mugrón mac Flainn (died 782), a previous king.Mac Niocaill, pg.127 He ruled from 783 to 803.in the Book of Leinster king list he is only given a reign of 3 years.
A conflict within the Uí Failge led to a slaughter in 789 at Cluain Ferta Mongáin (Kilclonfert, County Offaly) by Óengus at which his cousin Áed mac Tomaltaig was slain (their fathers were brothers).Annals of Ulster, AU 789.10; Donnchad Ó Corráin, New History of Ireland: Volume I, pg.601 In 803 he was treacherously killed by the followers of Fínsnechta Cethardec mac Cellaig (died 808), over king of Leinster.AU 803.6; Byrne, pg.160 Finsnechta was ensuring his control of the church of Kildare which led to conflict with the Uí Failge.
His grandson Máel Sinchill mac Mugróin (died 881) was a King of the Uí Failge.
Notes
See also Kings of Ui Failghe
References
Annals of Ulster at at University College Cork Byrne, Francis John (2001), Irish Kings and High-Kings, Dublin: Four Courts Press, Mac Niocaill, Gearoid (1972), Ireland before the Vikings, Dublin: Gill and Macmillan Ó Cróinín, Dáibhí (2005), A New History of Ireland, Volume One, Oxford: Oxford University Press Book of Leinster,Rig hua Falge at at University College Cork
External links CELT: Corpus of Electronic Texts at University College Cork