Arthurian legend vs fable

Arthurian legend and fable both are nouns.

Word	Noun	Adjective	Verb	Adverb
Arthurian legend	Yes	No	No	No
fable	Yes	No	No	No

As nouns, fable is a hypernym of Arthurian legend; that is, fable is a word with a broader meaning than Arthurian legend:

Other hypernyms of Arthurian legend include legend.

Arthurian legend (noun)	fable (noun)
the legend of King Arthur and his court at Camelot	a short moral story (often with animal characters)
	a story about mythical or supernatural beings or events
	a deliberately false or improbable account