Cath Maige Tuireadh (the (second) Battle of Magh Tuiredh) is a tale of the Irish Mythological Cycle in which the Tuatha Dé Danann defeat their enemies, the Fomorians. It expands on references to the battle in Lebor Gabála Érenn and the Irish Annals, and is one of the richest sources of tales of the former Irish gods. It is found in a 16th century manuscript, but the text is believed to date from the 11th century.

In the build-up to the battle it tells how Nuada lost the kingship of the Tuatha Dé after losing an arm, and regained it after a working silver arm was made for him by Dian Cecht and Creidhne. It also tells of the half-Fomorian Bres, who replaced Nuada as king, his conception (when his mother Ériu was visited by the Fomorian prince Elatha on a silver boat), his oppression of the Tuatha Dé, how he was deposed after being satirised for a lack of hospitality, and how he gathered the Fomorians under Balor to help him take back the throne by force, against the will of Elatha.

It also tells how Lug gained entry to Nuada's court, for although they already had a carpenter, a smith, a champion, a harper, a hero, a poet, a historian, a magician, a physician, a cup-bearer and a brazier, there was no-one in the court who possessed all these skills simultaneously. Lug won a flagstone-throwing competition with Ogma and entertained the court with his harp-playing, and Nuada began to wonder if this young man could lead the Tuatha Dé to victory over the Fomorians. Nuada abdicated in favour of Lug, who began making preparations for war.

The Trí Dée Dana, the three gods of art, Goibniu, Creidhne and Luchta, spent seven years making weapons. The Dagda kept a tryst with the Mórrígan in exchange for her assistance. Dian Cecht and his daughter Airmed blessed the well of Slane so it would heal their wounded. Lug sent the Dagda to spy on the Fomorians, but they humiliated him by making him eat a huge amount of porridge from a hole in the ground.

Both sides gathered for battle. Goibniu's smithing ensured that any broken or blunted weapons would return to the battle sharp and whole the following day, so the Fomorians sent an assassin, Ruadan, son of Bres and Brigid, to kill him. He wounded him with a spear which Goibniu had made for him, but Goibniu pulled it out and killed him with it. His wound was then healed in Dian Cecht's well.

The battle was long and bloody. Nuada and Macha, daughter of Ernmas, were both killed by Balor. Lug faced Balor, who opened his terrible, poisonous eye that killed all it looked upon, but Lug shot a slingstone that drove his eye out the back of his head, wreaking havoc on the Fomorian army behind. The Mórrígan urged on the Tuatha Dé and the battle became a rout.

Lug found Bres alone and unprotected on the battlefield, and Bres begged for his life. If he was spared, he promised, he would ensure that the cows of Ireland always gave milk. The Tuatha Dé refused the offer. He then promised four harvests a year, but the Tuatha Dé said one harvest a year suited them. But Lug spared his life on the condition that he teach the Tuatha Dé how and when to plough, sow and reap.

External links

• The Battle of Magh Tuireadh translated by Elizabeth Gray
• The Battle of Magh Tuireadh translated by Whitley Stokes