Ailill mac Echach Mugmedóin was an Irish prince, the son of the high king Eochaid Mugmedón (d.362) by his wife Mongfind, sister of Crimthann mac Fidaig (d.367). He was ancestor of the Uí nAilello dynasty of

Connacht Connacht or Connaught ( ; or ), is the smallest of the four provinces of Ireland, situated in the west of Ireland. Until the ninth century it consisted of several independent major Gaelic kingdoms (Uí Fiachrach, Uí Briúin, Uí Maine, C ...

. He lived in the late 4th century. "The Violent Death of Crimthann mac Fidaig and of the Three Sons of Eochaid Muigmedón" gives the story of the sons of Eochaid Mugmedón. According to this saga, his half-brother the high king Niall Noigiallach (d.405) made Ailill's full brother Fiachrae his champion and levier of rents and hostages on the death of their brother Brion. Ailill accompanied Fiachrae on a successful raid into Munster but Fiachrae was mortally wounded. After Fiachrae's death, Ailill was captured and executed by Eochaid mac Crimthainn of Munster. According to legend, he was buried at

Heapstown Cairn Heapstown Cairn is a cairn and National Monument located in County Sligo, Ireland. Location Heapstown Cairn is located on a low hill immediately west of the River Uinshin and north of Lough Arrow, northwest of Ballindoon Friary. History H ...

, County Sligo.

Notes

References

* Francis J.Byrne, ''Irish Kings and High-Kings'' * ''The Chronology of the Irish Annals'', Daniel P. McCarthy
Dan Wiley's site on the Cycles of the Kings
5th-century deaths Nobility from County Roscommon People from County Sligo 5th-century Irish people Year of birth unknown {{Ireland-royal-stub