Óengus Tuirmech Temrach, son of Eochaid Ailtlethan, was, according to medieval Irish legend and historical tradition, a High King of Ireland.
He was found and brought up by fishermen, and became the ancestor of several High Kings of Ireland and the later Dál Riata monarchs of Scotland.
The Lebor Gabála Érenn interprets his epithet as meaning "the reckoner of Tara", saying that "by him was 'reckoning' first made in Ireland".
[3] He reigned for thirty or sixty years, and died at Tara, succeeded by his nephew Conall Collamrach.
The Lebor Gabála synchronises his reign with that of Ptolemy VI Philometor in Egypt (180–145 BC).