Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. In Welsh
mythology, Gwydion is a magician appearing prominently in the Fourth
Branch of the Mabinogi and the ancient poem Cad Goddeu. He is the
brother of Gilfaethwy and Arianrhod, and the nephew of Math fab
Mathonwy. In the Mabinogion he is called the son of the goddess Dôn,
making it likely he is a euhemerized god or demi-god. The name Gwydion
(which should more properly be spelled Gwyddien in Modern Welsh, as can
be adduced from its Old Welsh form Guidgen; cognate with Old Irish
Fidgen) may be interpreted as "Born of Trees". In the Fourth Branch of
the Mabinogi, Gwydion helps his brother Gilfaethwy rape Goewin, Math's
foot-holder. To this end he steals Pryderi of Dyfed's pigs, thus forcing
Math away to fight a war (Math only took his feet from his foot-holder's
lap to go to battle). Gwydion and Gilfaethwy sneak back to Math's court
where Gilfaethwy rapes Goewin. When Math hears of this, he turns his
nephews into a series of mated pairs of animals: Gwydion becomes a stag
for a year, then a sow and finally a wolf. Gilfaethwy becomes a hind
deer, a boar and a she-wolf.
