Cobthach Cóel Breg or Cobthach Fion, son of Úgaine Mor, was, according to medieval Irish legend and historical tradition, a

High King of Ireland High King of Ireland ( ) was a royal title in Gaelic Ireland held by those who had, or who are claimed to have had, lordship over all of Ireland. The title was held by historical kings and was later sometimes assigned anachronously or to leg ...

. He took power after murdering his brother

Lóegaire Lorc Lóegaire Lorc, son of Úgaine Mor, was, according to medieval Irish legend and historical tradition, a High King of Ireland. The ''Lebor Gabála Érenn'' says he succeeded directly after his father was murdered by Bodbchad, although Geoffrey Kea ...

. The story is told that he was so consumed with jealousy for his brother that he wasted away to almost nothing, from which he gained his epithet ''Cóel Breg'', the "meagre of Brega". Acting on advice from a

druid A druid was a member of the high-ranking priestly class in ancient Celtic cultures. The druids were religious leaders as well as legal authorities, adjudicators, lorekeepers, medical professionals and political advisors. Druids left no wr ...

, he sent word to that he was ill, so that Lóegaire would visit him. When he arrived, he pretended to be dead. As he lay on his bier, Lóegaire prostrated himself over his body in grief, and Cobthach stabbed him with a dagger. He paid someone to poison Lóegaire's son, Ailill Áine, and forced Ailill's son Labraid to eat part of his father's and grandfather's hearts, and a mouse, and forced him into exile – according to one version, because it had been said that Labraid was the most hospitable man in Ireland. Cobthach later made peace with Labraid, now known by the epithet ''Loingsech'', "the exile", and gave him the province of

Leinster Leinster ( ; or ) is one of the four provinces of Ireland, in the southeast of Ireland. The modern province comprises the ancient Kingdoms of Meath, Leinster and Osraige, which existed during Gaelic Ireland. Following the 12th-century ...

, but relations broke down again and war broke out between them, and Labraid burned Cobthach and his followers to death in an iron house at Dind Ríg, marking a rift in the house of Erimon. He had ruled for either fifty or thirty years. The ''Lebor Gabála'' gives fifty, and dates his death to Christmas Eve, 307 BC. It also synchronises his reign with that of

Ptolemy II Philadelphus Ptolemy II Philadelphus (, ''Ptolemaîos Philádelphos'', "Ptolemy, sibling-lover"; 309 – 28 January 246 BC) was the pharaoh of Ptolemaic Egypt from 284 to 246 BC. He was the son of Ptolemy I, the Macedonian Greek general of Alexander the G ...

(281–246 BC). The chronology of Keating's ''Foras Feasa ar Éirinn'' dates his reign to 409–379 BC, that of the ''Annals of the Four Masters'' to 592–542 BC.''Annals of the Four Masters'
M4608-4658
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References

Legendary High Kings of Ireland 4th-century BC legendary monarchs Usurpers Fratricides Irish regicides {{Celt-myth-stub