or “the Grave of the Greyhound.” A ballad by the Hon. William Robert Spencer. The tale is that one day Llewellyn returned from hunting, when his favourite hound, covered with gore, ran to meet him. The chieftain ran to see if anything had happened to his infant son, found the cradle overturned, and all around was sprinkled with gore and blood. Thinking the hound had eaten the child, he stabbed it to the heart. Afterwards he found the babe quite safe, and a huge wolf under the bed, quite dead. Gêlert had killed the wolf and saved the child.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894