The Cath Maige Tuired (“The Battle of Mag Tuired”) is the great war story of Irish mythology. It tells how the Tuatha Dé Danann, the divine race of Ireland, threw off the oppression of the Fomorians — a race of monstrous, violent beings from beyond the sea — in a titanic battle on the plain of Mag Tuired (Moytura), near Lough Arrow in County Sligo. At its climax, the young god Lugh faces his own grandfather, Balor of the Evil Eye, whose single eye destroys everything it looks upon.
The main text survives in a sixteenth-century manuscript, but its language shows that it was composed in the ninth century or earlier. It is one of the most important sources for Irish mythology, full of the gods’ names, powers, and relationships, and it has been compared with the great divine wars of other Indo-European traditions — the Greek battle of gods and Titans, and the Norse war between the Aesir and Vanir.
The Oppression of Bres
After the first battle of Mag Tuired, in which the Tuatha Dé won Ireland from the Fir Bolg, their king Nuada lost his arm. Because a king had to be without blemish, he was replaced by Bres, a beautiful young man who was half Fomorian. It was hoped that his kingship would bring peace between the two peoples.
It did not. Bres was a miser and a tyrant. Under him, the Fomorian kings Elatha, Indech, and Tethra imposed a heavy tax on Ireland. The Tuatha Dé champions were reduced to hard labour: Ogma the champion had to carry firewood, and the great Dagda was forced to dig ditches and build a fortress for Bres. Bres gave no hospitality: guests left his house without the smell of ale on their breath or their knives greased with fat.
The poet Coirpre, given a tiny dark room with no fire, bed, or food, composed the first satire in Ireland against Bres:
Without food quickly served on a dish,
without a cow’s milk on which a calf grows,
without a man’s dwelling in the darkness of night,
without paying the company of bards — let that be Bres’s condition.
Blotches broke out on Bres’s face, and the Tuatha Dé demanded he step down. Meanwhile, Nuada’s arm had been replaced by a silver one, and then healed into flesh by the physician Miach, and Nuada was restored as king.
Bres went to his father Elatha among the Fomorians and raised a vast army, led by Balor and Indech, to reconquer Ireland.
Lugh Comes to Tara
As the Tuatha Dé prepared for war, a young stranger arrived at the gates of Tara, the royal seat. He was Lugh, son of Cian of the Tuatha Dé and Ethniu, daughter of the Fomorian Balor. The doorkeeper told him that no one could enter Tara without a skill.
Lugh offered his skills one by one: he was a carpenter, a smith, a champion, a harper, a warrior, a poet and historian, a sorcerer, a physician, a cupbearer, and a bronze-worker. Each time, the doorkeeper replied that the Tuatha Dé already had someone with that skill.
“Then ask the king,” said Lugh, “whether he has one man who possesses all these arts together. If he has, I will not enter Tara.”
No one had. Lugh was admitted and given the name Samildánach, “master of all arts.” He proved himself by beating the champion Ogma at throwing a flagstone and by playing the harp so that the court wept, laughed, and slept in turn. Nuada was so impressed that he gave Lugh his throne for thirteen days to lead the preparations for war.
Preparing for Battle
Lugh summoned each of the Tuatha Dé and asked what they would contribute. The answers are a catalogue of divine powers:
- Goibniu the smith: he would make a spear-head with three strokes of his hammer, and no spear he made would miss.
- Credne the bronze-worker would make rivets, sword hilts, and shield rims.
- Luchta the carpenter would make shields and spear shafts.
- Dian Cécht the physician: any warrior wounded, unless his head was cut off, would be healed by the next day.
- The sorcerers would cast the twelve mountains of Ireland onto the Fomorians.
- The cupbearers would bring a great thirst upon the Fomorians and hide the rivers and lakes from them.
- The druids would rain fire on the Fomorians and take away two-thirds of their strength.
- Coirpre the poet would satirize them so that they could not stand against the Tuatha Dé.
- The Morrígan and the women of magic would bind the enemy.
The Dagda and the Morrígan
Before the battle, at Samhain, the Dagda met the Morrígan at a river in Connacht. She was washing, with one foot on each bank. They lay together, and she promised to help the Tuatha Dé and to destroy the Fomorian king Indech (see The Morrígan).
The Dagda then went to the Fomorian camp to spy and negotiate a truce. The Fomorians, mocking his famous appetite, prepared a porridge for him in a pit in the ground: eighty gallons of new milk, with meal and fat, and whole goats, sheep, and swine boiled in it. They told him he would be killed if he did not eat it all. The Dagda took his ladle, big enough for a man and woman to lie in, and ate the whole thing, then scraped the bottom of the pit with his finger. Then he fell asleep, his belly as big as a house cauldron. It is one of the comic high points of Irish myth.
The Battle
The two armies met at Mag Tuired. For several days there were skirmishes, and the Fomorians noticed something strange: their weapons were broken and their warriors dead, but the Tuatha Dé’s weapons were renewed each morning and their dead came back to life.
The Fomorians sent a spy, Rúadán, the son of Bres and Brigid. He saw Goibniu forging spear-heads, Credne making rivets, and Luchta carving shafts, all in a flash. He also saw the well of Sláine, into which Dian Cécht and his children cast the dead and wounded while chanting spells, so they came out healed.
Rúadán asked Goibniu for a spear, and turned and threw it at him. Goibniu pulled the spear out of his own body and threw it back, killing Rúadán. His mother Brigid came and keened over his body — the first keening heard in Ireland.
The Fomorians filled the healing well with stones.
Balor of the Evil Eye
The great battle began. Nuada was killed by Balor. Balor was the most terrible of the Fomorians. He had a single enormous eye, whose lid had to be raised by four men with a polished handle. Once the eye was opened, whatever it looked upon was destroyed; an army that saw it could not withstand a few warriors. He had received its poison, the story says, when as a boy he looked through a window while his father’s druids were brewing a spell.
Lugh, who had been kept out of the battle for his own protection, broke free and entered the field. When the eye was opened against him, Lugh cast a sling-stone that struck it and drove it through the back of Balor’s head, so that it gazed upon the Fomorian army behind him, and they were destroyed. (In a later version, Lugh uses a spear.)
This was the fulfilment of a prophecy that Balor would be killed by his own grandson — a prophecy that had led Balor to lock his daughter Ethniu in a tower, in vain.
The Rout of the Fomorians
The Fomorians were driven back to the sea. The Morrígan kept her promise and fought in the battle, and Ogma and the Fomorian king Indech killed each other. Bres was captured. He begged for his life, offering first that the cows of Ireland would always have milk, then that there would be a harvest every quarter of the year. The Tuatha Dé refused both. Finally he offered the knowledge of when to plough, when to sow, and when to reap. For that, his life was spared.
The Prophecies of the Morrígan
After the victory, the Morrígan announced the triumph to the royal heights and the fairy mounds of Ireland. Then she spoke two prophecies.
The first was a poem of peace: “Peace up to the sky, sky down to earth, earth beneath sky, strength in each…”
The second was a vision of the end of the world, a time of moral collapse: “I shall not see a world that will be dear to me. Summer without blossoms, cows without milk, women without modesty, men without valour, captures without a king… every son a betrayer, every daughter a…” In its shape, it resembles the Norse Völuspá’s vision of the “axe age, sword age” before Ragnarök.
Meaning of the Battle
Scholars have read the battle in several ways:
- A divine war. Like the Greek war between gods and Titans, it establishes the order of the world by the victory of one generation of gods over an older, wilder race.
- A contest of functions. The French scholar Georges Dumézil argued that it reflects the three functions of Indo-European society — sovereignty, war, and fertility — and that the Tuatha Dé’s victory secures the right order of all three. Bres’s ransom, the secret of agriculture, is the crucial prize.
- Kingship. The fall of Bres, a king without generosity, and the rise of Lugh, master of all arts, shows what a true king must be.
Last reviewed: September 2026.