 Although Gwenddoleu plays no part in Arthurian legend, his court adviser Myrddin formed part of the basis for the later Arthurian legends concerning the wizard Merlin.In Geoffrey of Monmouth's "Vita Merlini", Myrddin (Merlinus) is said to have been driven mad with grief following the death of Gwenddoleu and to have fled into the Caledonian forest.The memory of both Gwenddoleu and Myrddin was preserved in Welsh literature.