E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Yniol.
An earl of decayed fortune, father of Enid, ousted from his earldom by his nephew Edyrn, son of Nudd, called the Sparrow-hawk. When Edyrn was overthrown in single combat by Prince Geraint, he was compelled to restore the earldom to Yniol. (Tennyson: Idyls of the King; Enid.)