Questions to consider . . .
Miranda Green’s Celtic Goddesses (BMP 1995), is a great introduction to the archaeological and literary sources for the better known Celtic goddesses. It’s out of print but you can still find second hand copies.
Epona.net is also a ‘scholarly resource’ and includes several primary sources for Epona’s cult in Roman Europe.
Notes and References
There is in the northern and farther part of Ulster . . . a certain people which is accustomed to appoint its king with a rite altogether outlandish and abominable. When the whole people of that land has been gathered together in one place, a white mare is brought forward into the middle of the assembly. He who is to be inaugurated, not as a chief, but as a beast, not as a king, but as an outlaw, has bestial intercourse with her before all, professing himself to be a beast also. The mare is then killed immediately, cut up in pieces, and boiled in water. A bath is prepared for the man afterwards in the same water. He sits in the bath surrounded by all his people, and all, he and they, eat of the meat of the mare which is brought to them. He quaffs and drinks of the broth in which he is bathed, not in any cup, or using his hand, but just dipping his mouth into it round about him. When this unrighteous rite has been carried out, his kingship and dominion have been conferred.
Fulvius Stellus hated women and used to consort with a mare and in due time the mare gave birth to a beautiful girl and they named her Epona. She is the goddess that is concerned with the protection of horses. So [said] Agesilaüs in the third book of his Italian History.
Rhiannon summoned wise and learned men. And when she thought it better to accept her punishment than argue with the women, she accepted her punishment. This is what it was: to stay at that court in Arberth for seven years. And there was a mounting-block outside the gate—to sit by that every day, and tell the whole story to anyone whom she thought might not know it, and offer to carry guests and strangers on her back to the court if they permitted it.
At that time Teyrnon Twrf Liant was lord over Gwent Is Coed, and he was the best man in the world. In his house he had a mare, and throughout his kingdom no stallion or mare was more handsome. And every May eve she would give birth, but no one knew at all what became of her foal.
. . . ‘God’s vengeance upon me’, he said, ‘if I do not find out what fate befalls the foals—tonight is May eve.’ He had the mare brought indoors, and he armed himself, and began the night’s vigil. As it begins to get dark the mare gives birth to a big, perfect foal which stands up on its feet immediately. Teyrnon gets up to examine the sturdiness of the foal. As he is doing this he hears a loud noise, and after the noise an enormous claw comes through the window, and grabs the foal by its mane.
Teyrnon draws his sword and cuts off the arm at the elbow so that that part of the arm, and the foal with it, are inside. Then he hears a noise and a scream at the same time. He opens the door and rushes off after the noise. He cannot see the cause of the noise because the night is so dark; but he rushes after it, and follows it. Then he remembers that he has left the door open, and he returns. And by the door there is a small boy in swaddling-clothes with a mantle of brocaded silk wrapped around him.
These thoughts were interrupted by my catching sight of a statue of the goddess Epona seated in a small shrine centrally placed, where a pillar supported the roof-beams in the middle of a stable. The statue had been devotedly garlanded with freshly picked roses. So in an ecstasy of hope on identifying this assurance of salvation, I stretched out my forelegs and with all the strength I could muster, I rose energetically on my hind legs.