In Irish mythology, Bres, aka Eochaid Bres, Eochu Bres ("Eochaid/Eochu the Beautiful"), was a king of the Tuatha Dé Danann. His parents were Prince Elatha of the Fomorians and Ériu. He was an unpopular king, and favoured his Fomorian kin. He grew so quickly that by the age of seven he was the size of a 14-year-old.
In the First Battle of Magh Tuiredh, King Nuada of the Tuatha Dé Danann lost his hand; because he was imperfect, he could not be king. Hoping to reconcile relations between the Fomorians and the Tuatha Dé Danann, Bres was named king and Brigid of the Tuatha de Danann married him.
Bres made the Tuatha Dé Danann pay tribute to the Fomorians and work as slaves: Ogma was forced to carry firewood, and the Dagda had to dig trenches around forts. He neglected his duties of hospitality: the Tuatha Dé complained that after visiting his house their knives were never greased and their breaths did not smell of ale. Cairbre, poet of the Tuatha Dé, composed a scathing poem against him, which was the first satire in Ireland, and everything went wrong for Bres after that.
After Bres had ruled for seven years, Nuada had his hand, which had formerly been replaced with a silver one by Dian Cecht and Creidhne, replaced with one of flesh and blood by Dian Cecht's son Miach, with the help of his sister Airmed; following the successful replacement, Nuada was restored to kingship and Bres was exiled. He went to his father for help to recover his throne, but Elatha would not help him gain by foul means what he had been unable to keep. Bres was guided by his father to Balor, another leader of the Fomorians, for the help he sought.
He led the Fomorians in the Second Battle of Magh Tuireadh but lost. He was found unprotected on the battlefield by Lugh and pleaded for his life. Lugh spared him because he promised to teach the Tuatha Dé agriculture.
In the Lebor Gabála and Cath Maige Tuired, Bres is portrayed as beautiful to behold, yet harsh and inhospitable. However, a poem of the dindsenchas praises Bres' "kindly" and "noble" character and calls him the "flower" of the Tuatha Dé Danann. It also tells of his death at the hands of Lugh. Lugh made 300 wooden cows, and filled them with a bitter, poisonous red liquid which was then "milked" into pails and offered to Bres to drink. Bres, who was under an obligation not to refuse hospitality, drank it down without flinching, and it killed him.
The name may be derived from Proto-Celtic *bregso-s ‘the glittering one,’ an extended form of the Proto-Indo-European root *bhreg- ‘to shine white, to glitter’ , whence comes the English words bright, birch and frigid via Latin.