mythological origins of Ireland

In Irish legend, an epic struggle was fought for control of the island between successive waves of supernatural and mortal settlers. These included the demonic Fomorians, the original inhabitants of Ireland, led by the giants Balar and Bres; the Fir Bolg; and the Tuatha Dé Danann (‘people of the goddess Danu’), a race with magical powers.

The Tuatha Dé Danann, led by Danu's son Nuada, defeated their predecessors, the Fir Bolg, in the first battle of Moytirra. The Fir Bolg were permitted to retire to Connacht, but Nuada lost his arm in the battle and Bres of the Fomorians took control. After Bres was ousted, Nuada, fitted with a cunningly wrought silver hand by the healer Dian Cécht, retrieved his throne. The Fomorians were finally defeated at the second battle of Moytirra, which culminated in the victory of the god-hero Lugh in single combat against Balar. The Tuatha Dé Danann were eventually defeated by the Milesians (the Celts), mortal ancestors of the Gaels.

According to Gaelic tradition, many tribes of the Tuatha Dé Danaan retired to a distant country beyond the western horizon known as Tír na n'Óg (‘land of eternal youth’), while the remainder withdrew to a subterranean otherworld to rule over the fairy folk, leaving Ireland to the mortals.

Stories of the legendary conquest of Ireland are recounted in the early medieval Lebor Gabála Érenn/Book of Invasions, which chronicles the history of Ireland from Creation to the 12th century, and in medieval hero-tales, such as the epic Cath Muighe Tuireadh/The Battle of Moytirra.