Tuatha Dé Danann means 'the people of the goddess Danu.' The Tuatha were a mythical people associated with ancient Ireland. Legend has it that they had perfected the use of magic, and that they travelled to Ireland on a large cloud and settled there.

They defeated the Fir Bolg people at the first battle of Mag Tuireadh. At the second battle of Mag Tuireadh, they defeated the Fomorians, a race of giants.

The Tuatha were driven to the underworld by the Milesians. They still live there as invisible beings called the Aes sidhe. They still fight beside mortals in just battles and go armed with lances of blue flame and shields of pure white.