The Tuatha de Danaan book

The content of the book is articulated in three cycles, organized in scrolls of vellum in the original version, that although is extremely fragmentary. Most of the copies that have survived to our times are documents manually transcribed in the subsequent centuries, therefore subject to potential revisions.

The first cycle narrates the tale of how the original members of the tribe arrived in the sky of Phaldorya creating the constellations to live in. They were Danu and her husband Dagda, Dian Cecht and his wife Ernmas, Rhiannon, the elders Oghma and Macha and they travelled through the space with a boat of the divine merchant Lugh that was navigated by Lyr. Before that time the sky was a place of darkness and the only creatures that were brave enough to roam in it were the ancient dragons, creatures of pure magic, and the fomorn, creature of pure evil and chaos. The ancient dragons confrontated the new comers in a challenge of wits but, impressed by the wisdom of members of the tribe accepted them as the new overlords of the sky. With the fomorn instead there were centuries of fights, until they've managed to banish them away temporarily. At the end of the first cycle Danu is elected queen of the tribe and Dagda becomes her king, granting a time of peace and order to the dark sky of Phaldorya, the palaces where they live can be seen from Phaldorya shining as stars and conformating the constellations, were the most devoted worshippers of the tribe are hosted in the afterlife.

The second cycle, also known as The cycle of births, recounts the years of peace that followed the arrive of the tribe. Governed by Danu and under the judicial authority of Dagda, the Tuatha de Danaan granted prosperity to the creation and thrived. Through countless years the souls of the people who died respecting their precepts were called to spend eternity in the service and company of the deities they pleased in life, the souls of the ones who spent a self-fulfilling life instead would be sent in the darkness to spend the eternity with the fomorn. Occasionally a fomor war band would try to attack the palace of one or another deity getting repelled invariably into the darkness were they belonged. The tribe started to expand, from the love between Danu and Dagda, three new deities were generated: Be Chuille, Brigid and Nuada; Dian Cecht's and Ernmas' offspring, Aine married Lugh and gave birth to three sons Luchtaine, Goibniu and Creidhne, who grew up to be prodigious artisans. Be Chuille travelled the dimensions to master the power of magic, gathering her knowledge from the ancient dragons and from her relationship with one of them was generated Clidnha who mastered the necromancy. Lyr and Rhiannon were joined in an open relationship, in love with each other but having occasional affairs with other divinities: in a time of passion between Nuada and Rhiannon was generated Boann, destined to suffer for their not-returned love for Rhiannon's lover. From the marriage between Brigid and Luchtaine were born Morrigan, the mistress of shapeshifters and amazons, and Aengus, who transformed a mortal woman into the goddess Fand.

The third cycle, also known as Exile, conquest and reconquer cycle, begins with the arrival of Balor who was originally an archmage, who learned the skills to travel between dimensions, tried to convince Be Chuille and, later, her daughter Clidnha to grant him immortality and knowledge. He tried also to steal artifacts owned by the gods, therefore Dagda exiled him to the darkness together with the fomorn. Several eons later Balor managed to unify the fomor people and, in a powerful battle to defeat Dagda and his people, severing Nuada's arm too. The tyrant obtained the services of Fand, that would give birth to their daughter Badb, and dominated the skyes with ruthless violence. Finally, betrayed by Fand, he would have no other choice than face the reforged forces of the tribe, guided by Nuada, that managed finally to vanquish him. The routing multitudes of fomorn returned to the darkness and the order was restored. Nuada, became the new leader of the tribe, under the guidance of his parents.

The fourth and final cycle of tales is a prophecy about the end of time, when in a distant future Xabrynth, a giant serpent-dragon entity after collecting the energy of all ancient dragons and fomorn, wreaks havoc in the skyes controlled by the tribe. Nuada, Morrigan and other gods try to fight the beast off but, for their dismay, they discover that cutting off one head of the beast makes regenerate two without any effect on the beast itself. Clidnha and Macha, get consulted to know if they see any chance to stop the beast, and Macha suggests that the only way the beast can be stopped is by surrendering everyone's living energy to create a unity in balance from chaos.

And so, in the unfathomable depths of the sky finally balance was restored, until a new spark of creation will be triggered and new struggles shall begin. And this story shall also be told.

— Herbert of Alkar.