Loomis explores the theory that the Arthurian Romances are based on Celtic Myths, transmitted to French by Breton bards. He explores the links between the Irish Sagas, the Welsh Mabinogion, and the various forms of the Arthurian Legends. He links Gawain with the Irish hero Cuchulain, Merlin to Mider, and the Grail to the cauldron of the Dagda and the Lia Fail.