Known as Rhiannon in Wales, Macha in Ireland and Epona to the Gauls this ancient horse goddess is one of the most well known of all the Celtic gods and goddesses. Horses played an important role in Celtic society. Naturally the protector of horses would play an equally important role. Epona has been revered since the Iron Age. She is the protector of horses, stables, and horse owners; she is the guardian of agriculture and transportation. In addition, Epona has been associated with birds; her birds were said to have the ability to put the living to sleep and to rouse the dead. She has also been pictured with cornucopias and baskets filled with fruits especially apples and thus been linked to fertility.

She is often portrayed riding a horse, next to a horse, surrounded by several horses and feeding foals. In parts of central Europe she was believed to be a magical white horse that brought shamans to the spirit world.

Epona translates as "divine mare" or "mare goddess". Small shrines, known as aediculae, were built in her honor by horse owners and often decorated with roses. More inscriptions, statues, and shrines dedicated to Epona have been found than for any other Celtic god or goddess. Even the Romans adopted this Celtic goddess. Her statues can be found along side other Roman Gods and Goddesses. Greek author, Agesilaos, tells the story of Epona's birth. A women-hating man named Furius Stellus had relations with a mare, who in turn gave birth to Epona, who had the ability to take human or horse form.

As with most gods and goddess in history, at least one day is set aside just to honor them. Epona's celebration is held on June 13th not to be confused with the The Festival of Epona on December 18th. The festival is a Roman celebration, the only celebration by the Romans to honor a Celtic deity.