Not much is known of the Tuatha de Danaan prior to their invasion of Ireland, other than that they came from four northern cities, Falias, Glorias, Murias and Finias, where they acquired their occult skills and attributes. On arriving in Ireland they burned their boats behind them to prevent themselves from being tempted to return.
They then fought two battles, the [Battle of Magh Tuiredh]?, in which they defeated the Tir Bolg, and the [Second Battle of Magh Tuiredh]? against the Formarians?.
A third battle was fought against a subsequent wave of invaders, the Milesians? who overcame the goddess, Eriu? whom the Tuatha de Danaan sent against them. The Milesians were magnanimous in victory and named the island Erin, the dative form of her name, in her honour. Defeated, the Tuatha were led underground by the Dagda?.