The Tuatha Dé Danann are one of five ancient Atlantean races, thought to have been lost for centuries. They live in the undersea city known as Thierna Na Oge. They were worshiped as gods by the people of pre-Christian Ireland.
Thierna Na Oge is one of the several city-states that were once part of the greater Pre-Cataclysmic Atlantean empire. Millennia ago, geological upheaval devastated Atlantis causing the entire continent to sink beneath the waves. While many Atlanteans survived to later establish the cities of Poseidonis and Tritonis, others migrated towards the outer regions to develop smaller, simpler settlements.
Thierna Na Oge eventually became known as one of the fabled Five Lost Cities of Atlantis. Its citizens evolved and adapted to life under the sea. They remained as a fiercely isolationist community, and after several generations, all of the city's dwellers developed golden orange skin and aqua-green hair.
Unlike their Atlantean brethren, the citizens of Thierna Na Oge rejected the logic of science and embraced the majesty of magic, much the same as their forbearers once did eons ago. Maintaining close ties to their mystical heritage, they grew into a society which became known as the Tuatha dé Danann. Under the watchful guidance of their matron goddess, Dana, members of the Tuatha recovered an important Atlantean artifact – one of the twelve fabled Zodiac Crystals. They encased the crystal into a royal seal which eventually became known as the Lia Fail. The Lia Fail granted its owner the ability to weave the multicolored threads of ambient magical energy that made up the fabric of all creation. Whoever took possession of the Lia Fail commanded great power and earned the right to call themselves King of Thierna Na Oge. Over the years, many have assumed the role of the monarch, and the title of King was shared between both male and female rulers (there was no feminine analogous title; all rulers were referred to as King).
Thierna Na Oge remained a lost city for centuries, but in recent years, the ruling council of Poseidonis had learned of the city's location and established a dialogue with them. Aquaman, the former King of Atlantis traveled to Thierna Na Oge and became embroiled in a civil war between the former benevolent king, Nuada Silverhand, and her sister, the ambitious King Bres. The incident revolved around the theft of their sacred Lia Fail. Bres believed that Nuada had misused the crystal's power, and had conspired with Aquaman to remove it from Thierna Na Oge, but in truth, Aquaman's evil stepbrother, the Ocean Master was the one truly responsible for stealing the powerful gemstone.
King Bres sentenced Nuada and Aquaman to die, but they managed to escape and fought with the Ocean Master in the hopes of recovering the Lia Fail. Their quest proved successful and Nuada was placed back upon the throne of Thierna Na Oge.
As the years passed, Aquaman worked alongside Nuada to reunify the members of the Tuatha De Danaan with that of modern Atlantean society. Their labors paved the way towards discovering the remaining four Lost Cities of Atlantis.
- The Tuatha Dé Danann are loosely based on a tribe of ancient Irish settlers known throughout Celtic and Irish mythology.