Lugh is one of the great gods of the Irish mythological tradition — a solar deity of extraordinary breadth, associated with skill, craft, light, and the harvest. His epithet Lámhfhada — Long Arm — refers both to his spear that never misses its mark and to the reach of the sun's rays across the world. He is patron of every art simultaneously: a scene at the gates of Tara in which he demands entry by listing his skills, only to be told each time that the Tuatha Dé Danann already has someone with that skill, until he points out that no one among them masters all of them at once, is one of mythology's great moments of divine self-presentation.
When Lugh arrives at the gates of Tara seeking entry among the gods, the doorkeeper asks his craft. He answers: smith. The doorkeeper replies that they have a smith. He answers: champion. They have one. Poet, historian, hero, sorcerer, physician, cupbearer — to each the answer is the same. Then Lugh asks: do you have anyone who is all of these things at once? The gates open.
This multiplication of skills is theologically significant. Lugh is not a specialist deity but a deity of excellence itself — of the principle of mastery applied to any domain. He is the divinity of human potential at its fullest extension, the archetype of the complete person rather than the specialised one.
Lugh founded the festival of Lughnasadh — held on the first of August — in honour of his foster mother Tailtiu, who died of exhaustion after clearing the plains of Ireland for agriculture. The festival marks the beginning of the harvest: the first fruits, the testing of the new grain, the games and assemblies that brought communities together before the long work of harvest began.
Lughnasadh is one of the four great Irish seasonal festivals (alongside Samhain, Imbolc, and Bealtaine) and has survived into modern paganism as one of the Wheel of the Year's eight stations. Its themes — first harvest, gratitude, the death of summer's abundance into autumn's labour — make it a festival of bittersweet fullness: the peak before the descent.
Lugh's festival is not a celebration of victory. It is a commemoration of sacrifice — of Tailtiu's exhaustion in service of the people's survival. The harvest is given only through someone's dying. Lugh does not let this be forgotten.
— Alexei Kondratiev, The Apple Branch: A Path to Celtic Ritual