In the Mythological Cycle of Irish Mythology the Tuatha Dé Danann lived in the other-world and were a magical race who became known as the Sidhe Faerie Folk in Irish folklore. They descended from the people of Neimheadh who were the second wave of settlers to arrive in Ireland.
The arrival of Tuatha Dé Danann to Ireland
When the Fir Bolg ruled Ireland their King, Eochaid mac Eirc, had a dream foretelling him about the arrival of a group of ships.
Led by King Nuada a fleet of 300 ships of the Tuatha Dé Danann arrived in Ireland. When they came ashore they set fire to their ships to hide their arrival but also to stop themselves from having to retreat from Ireland. Smoke from these fires could be seen for miles and filled the sky for 3 days and 3 nights.
Four Treasures of the Tuatha Dé Danann
The Tuatha Dé came from four mythical cities of islands in the north called Findias, Gorias, Murias, and Falias where they learned the skill of wisdom and magic. From these cities they brought four treasures to Ireland, Dagda’s Cauldron, the Spear of Lugh , the Stone of Fal, and the Sword of Light of Nuada.
Each of the treasures held special properties such as Dagda’s Cauldron that would leave no company unsatisfied. No battle was ever sustained against the Spear of Lugh or he who held it. No one ever escaped from the Sword of Light of Nuada once it was drawn from its sheath and the Stone of Fal (stone of Ireland) would cry out under kings of Ireland.
Battles of the Tuatha Dé Danann
When the Tuatha Dé Danann arrived in Ireland the Fir Bolg were the leaders of the land. The Tuatha Dé marched to the west coast and demanded half of the Irish land. The Fir Bolg refused to give then any of Ireland and the first battle of Mag Tuired (Moytura) ensued. The Fir Bolg were defeated and fled Ireland forever.
During the battle of Moytura King Nuada of the Tuatha Dé had his right hand served so the kingship was handed to Eochu Bres who was a ruthless leader and oppressed the Tuatha Dé because of his ancestry. When Nuada had his hand replaced with a hand made from silver he retook back leadership from Bres which angered him. Bres turned to help from the King of the Fomorians, Balor of the evil eye, who agreed to build a large army.
King Nuada assigned a new member of Tuatha Dé, Lugh, to lead his army into battle against the Fomorians. Lugh was a young man who was skilled with the spear.
During the second battle of Moytura King Nuada was killed by Balor but Lugh, who was Barlors grandson, killed him with his slingshot. Lugh fired his slingshot at Barlor striking him in his eye causing chaos within the ranks of the Fomorians allowing the Tuatha Dé to win the battle.
Bres was captured and his life was spared as long as he taught the Tuatha Dé Danann how to plough, sow and reap.
A third battle took place when the Milesians invaded Ireland and faced three goddess Ériu, Banba and Fodla. Their husbands Mac Cuill, Mac Cecht and Mac Gréine who were all Kings of Tuatha Dé requested a truce after three days of battle. The Milesians agreed to the truce and anchored off shore. The Tuatha Dé cast a magical spell creating a fierce storm in attempt to destroy or drive the Milesians away from Ireland. This plan failed when an Milesian poet by the name of Amergin was able to cast a verse to calm the sea. Once the sea calmed the Milesian’s came back onshore and defeated the Tuatha Dé Danann at Tailtiu.
How the Tuatha Dé Danann became Faerie Folk
Ireland was divided between the two factions, the Milesians would stay above ground and the Tuatha Dé below ground into Sidhe mounds. Deprived of offerings and affection the Tuatha de Danann shrivelled and withered until they became the little people or the Faerie Folk.