Major Tuatha Dé Danann figure; samildánach (master of all crafts) and lámfada (long-armed). King of the Tuatha Dé during the Second Battle of Mag Tuired campaign, when he killed his maternal grandfather Balor of the Evil Eye with a sling-stone through the eye. Inaugurator of the Lughnasadh harvest assembly at Tailtin in honor of his foster-mother Tailtiu. Continental cognate Lugus attested across Gaul and Iberia (Lugdunum, Lugudunum, Luguvalium, etc.). Father of Cú Chulainn by Deichtire under the dominant Compert Con Culainn tradition.
Cath Maige Tuired (The Second Battle of Mag Tuired, surviving in 16th-c. Harleian MS 5280 from earlier compilation); Lebor Gabála Érenn (c. 11th c. CE); Compert Con Culainn (Lebor na hUidre c. 1100 CE); Tochmarc Emire