I've also a children's book by Gwyn Jones, "Welsh Legends and Fairy Tales" (Puffin), which deals with the Mabinogion stories among others, and a book by Roger Sherman Loomis, "Celtic Myth and Arthurian Romance" (Constable), which discusses - (why I am tempted to say?) - the mythic history, King Arthur's and Sir Caradoc's.
I was taught Greek stories in literature at school, but found Celtic tales as rivetting, when I found them. It is odd that we English dumped ours. Weren't they any good? Mind you, a recent History Today identified the landscape described in Beowulf (not that it is attributed to) as the Isle of Sheppey. Quite convincing, but not quite Glastonbury.
And Morgan may be late, but she is interesting, whereas the character in this recent production is an empty headed little scatterbrain with big hair.