The Wars of the Gods: Four, Fomorians and Faeries

They were there first, waiting as the newcomers tried their hand at taking the land from them. Massive, monstrous, having come from beneath the sea or beyond it, the Fomorians waited and held the land for their own. They were the old ones, the ancient, and all the younger gods who came after had to contend with them. Time and again they came and failed, slaughtered or shattered by disease. The invaders left or died, one after another, but always the Fomorians remained and waited. Giants, some called them, with limbs and heads of beasts. Others say they had one eye, one leg and one arm. But we know, for sure, that some were beautiful and all were mighty. They wielded terrible magics and mysterious skills, and from them came the greatest treasure of all the British Isles, the Cauldron of Rebirth - the Grail. 

The Gundestrup Cauldron