Cath Maige Tuired (Modern Irish: Cath Maighe Tuireadh; translated as "The Battle of Magh Tuireadh") is the name of two saga texts from the Mythological Cycle in Irish mythology. These texts describe battles fought by the Tuatha Dé Danann. The first text tells of a battle between the Tuatha Dé Danann and the Fir Bolg. The second text describes a battle between the Tuatha Dé Danann and the Fomorians.

Etymology

The Old Irish place name Mag Tuired (Modern Irish: Magh Tuireadh; translated into English as Moytura or Moytirra) is thought to mean "plain of pillars" or "plain of towers." It refers to two different locations, both in Connacht: the first is near Cong, County Mayo, on the border with County Galway, in the area of Conmaicne Cuile; the second is near Lough Arrow in County Sligo.

The First Battle of Mag Tuired

This text tells the story of how the Tuatha Dé Danann took control of Ireland from the Fir Bolg, who lived there before them. It begins with the children of Nemed, an earlier group of people in Ireland, leaving the island to go to Greece because they were being mistreated by the Fomorians. Later, some of Nemed’s descendants, called the Fir Bolg, returned to Ireland and ruled the land for thirty years until the arrival of the Tuatha Dé Danann, who were also descendants of Nemed.

The Tuatha Dé Danann, led by their king, Nuada, traveled to Ireland in 300 ships from the northern islands. Their arrival was predicted in a dream by Eochaid mac Eirc, the king of the Fir Bolg. When the Tuatha Dé Danann landed, they burned their ships. Talks began between Sreng, the champion of the Fir Bolg, and Bres of the Tuatha Dé Danann. Bres asked the Fir Bolg to either fight or give them half of Ireland. The Fir Bolg chose to fight. After preparing weapons, the two groups met at the Pass of Balgatan, and the battle lasted four days. Nuada fought Sreng, and Sreng cut off Nuada’s right hand. Despite this, the Tuatha Dé Danann became stronger. A truce was made, and the Fir Bolg had three choices: leave Ireland, share the land, or continue fighting. They chose to fight again. Sreng challenged Nuada to a one-on-one battle, but Nuada asked Sreng to tie up one of his arms to make the fight fair. Sreng refused. Instead, the Tuatha Dé Danann offered the Fir Bolg one of Ireland’s provinces. Sreng chose Cóiced Ol nEchmacht, and peace was made.

Dian Cecht, the god of doctors, created a silver hand for Nuada, and Nuada was then called Nuada Airgetlám, meaning "Nuada of the Silver Hand." However, the goddess Brigid had told the Tuatha Dé Danann that no one with a physical injury could rule them. Because Nuada had lost a hand, the Tuatha Dé Danann chose a new king, Bres, the son of Elatha, who was the king of the Fomorians or the Children of Domnu. Seven years later, Bres died after drinking while hunting. Nuada, now with his silver hand, was restored as king.

The Second Battle of Mag Tuired

The second text of this name is also called Cath Dédenach Maige Tuired ("The Last Battle of Mag Tuired"), Cath Tánaiste Maige Tuired ("The Second Battle of Mag Tuired"), and Cath Maighe Tuireadh Thuaidh ("The Battle of Northern Mag Tuired"). It describes how the Tuatha Dé Danann, after conquering Ireland, face harsh treatment from the Fomorians. They then fight a battle to free themselves from this mistreatment. The story adds more details about the battle mentioned in Lebor Gabála Érenn and the Irish Annals. It is one of the most important sources for stories about ancient Irish gods. The text is found in a 16th-century manuscript, but it is believed to have been created in the 12th century by combining older material from the 9th century.

The story begins with a short description of the first battle, when Nuada loses his arm and is replaced as king by Bres. It then explains how Bres was born from a union between Ériu of the Tuatha Dé Danann and Elatha of the Fomorians. Because of his mixed heritage, Bres mistreats the Tuatha Dé Danann by forcing them to do hard work and demanding heavy payments. He also fails to act as a kind and generous ruler. Bres is removed from his position as king, and Nuada, whose arm is replaced with a silver one by the healer Dian Cecht (whose son, Miach, helped the arm heal), is restored to leadership. Bres asks the Fomorians for help to reclaim his throne. Although his father, Elatha, refuses, another Fomorian leader named Balor of the Evil Eye agrees to support him and gathers a large army. Meanwhile, Lugh, who is also the child of a Tuatha Dé Danann and a Fomorian, arrives at Nuada’s court. After showing his many skills, Lugh is given command of the Tuatha Dé Danann. During the battle, Nuada is killed by Balor. However, Lugh, who is Balor’s grandson, defeats the Fomorian leader by throwing a stone with his sling, breaking Balor’s dangerous eye and causing chaos among the Fomorians. After the battle, Bres is found alive and is allowed to stay free only if he teaches the Tuatha Dé Danann how to farm. Finally, Lugh, the Dagda, and Ogma recover the Dagda’s harp, Uaithne, which had been taken by the retreating Fomorians.