Sidhe Legends Series by Kenneth C. Flint

A boy, Lugh Lamfada, escapes the destruction of his home by sinister forces. Rescued by sea-god Manannan MacLir, Lugh is sent into Eire on a mission: to aid the Tuatha de Darnann, enslaved by monstrous pirates called Fomor. Lugh boldly invades the Fomor headquarters, a Tower of Glass, and discovers that the Fomor are the ones who destroyed his home. Through intrigues, battles, and the help of odd, new friends, Lugh challenges the Fomor and their giant, armored leader: Balor One-Eye... moreA boy, Lugh Lamfada, escapes the destruction of his home by sinister forces. Rescued by sea-god Manannan MacLir, Lugh is sent into Eire on a mission: to aid the Tuatha de Darnann, enslaved by monstrous pirates called Fomor. Lugh boldly invades the Fomor headquarters, a Tower of Glass, and discovers that the Fomor are the ones who destroyed his home. Through intrigues, battles, and the help of odd, new friends, Lugh challenges the Fomor and their giant, armored leader: Balor One-Eye. Manannan supplies Lugh with the Riders, a magical warrior troop. In a final confrontation, the Formor hold on the Dananns is broken. Balor and Tower of Glass, however, are still a threat. The Riders of the Sidhe is Book One of "The Gods of Eire" trilogy, an epic retelling of Celtic legend, filled with fire and magic of the ancient bards. less

When the evil lord Balor and his dark Druid Mathgen order the traitorous Bres to recapture the isle of Eire, young Lugh and his band of champions pledge to defend their homeland.

Now the final battle approaches. The races of Erin join to free their homeland from the foul Fomor and their nightmare engines. But the evil lord Balor plans a fearful vengeance, and captures the sea-god Manannan MacLir. On a deadly mission go the Champions of Eire: young Lugh, the Master of the Silver Warriors; his beloved Aine; the fearless Taillta; Morrigan, the Raven warrior-woman; Shaglan, the Pooka Shapeshifter; the mighty Dagda and his brave son Angus.