So What's the Deal with Llew? Part One: Llew's Birth Myth

Arianrhod's lone surviving myth, and the one which has caused confusion regarding her for scholars and pagans alike over many years, comes to us from The Mabinogion.

First, here's an overview of the myth:

The king of Caer Dathyl was Math, a renowned magician and uncle to Arianrhod. Math had a "footholder" a beautiful maiden named Goewin. Basically, the "footholder's" job was to rule the Kingdom in time of peace. The catch was that the footholder had to be a virgin.

Arianrhod had two brothers, Gwydion and Gilvaethwy (yes, I know that second one is a mess of consonants, welcome to Welsh myth).  Both were mischief making cut-ups, especially Gwydion, who was also Math's apprentice.

Unfortunately, Gilvaethwy fell in lust with Goewin and decided he had to have her. Gwyidion decided to help. Knowing that Goewin was in constant attendance on Math, and the only way to get rid of Math was to have him go to war, Gwydion stole some of the pigs belonging to the ruler of a neighboring kingdom, King Pryderi. Pryderi was angry (these were special magickal underworld pigs) and he and Math went to war.

Meanwhile, Gilvaethwy waltzed into his uncle's castle, bade all the attendants to leave except Goewin and raped the maiden right on his uncle's couch.

Well, when Math returned, he was none too happy. He realized that the war had been started by Gwydion's magick, that hundreds of good men - including Pryderi himself - had been killed, and further, he learned of Goewin's rape. Punishment was inevitable. Pulling out his magickal wand, Math touched Gwydion and Gilvaethwy into a mated pair of deer and sent them out into the woods for a year and a day.

A year later the two of them returned, and with them, a young fawn which Math named Hydwyn. Obviously feeling that the young men hadn't been punished enough yet, Math touched them with his wand again and turned them into wild hogs, and again set them lose for a year and a day. This time, on their return they had a young hog, which Math named Hychdwyn.

Naturally the punishment wasn't over (because everything happens in threes, right?) and Math turned his nephews into a pair of wolves. A year and a day later they returned, this time with a wolf cub, which Math named Bleiddwn.

At this point Math decided they'd had enough of this sort of punishment and turned them back into humans. During the intervening time, Math had married Goewin but his kingship was in danger because he received his sovereignty through her, and now that she was no longer virgin, this was in question. Naturally, it was Gwydion and Gilvaethwy's job to find a replacement footholder.

So Arianrhod is summoned to Caer Daethyl and told that she's going to be the new footholder. Math asks her if she is a maiden and Arianrhod says, "I know not but that I am." Now this is one of the pertinent points that has been mucked up and confused over the years, so we'll get in depth regarding that in a later post.

Math (obviously not trusting the brothers - would you?) asks Arianrhod to step over his wand to prove her maidenhood. She does so and immediately gives birth to two sons. Dylan scampers off into the waves (becoming a god of the Sea) and the other was an unformed blob. Arianrhod was horrified (wouldn't you be?) and ticked off and leaves, and Gwydion takes the blob/baby and puts him in a chest (the world's first incubator) and adopts him.