Epona is a Gallo-Celtic goddess who made her way into the Roman pantheon, where she was worshipped as the protectress of horses and foals. Shrines were found in almost every stable. It is thought that in early times, she was believed to be an incarnation of the Divine White Mare.
Epona was originally a great nature-mother goddess of her own right. Without a husband or children she lived as the virgin self-producing Great Mother. She is sometimes addressed in the plural form Eponabus, which seems to be an indication that she may have been as Matrone and was thought to be three-formis and a goddess of fertility. "The Holy Queen Epona" was portrayed riding on a horse, followed by foals, dogs and birds. She is shown half-naked or wearing a wide coat.
Sometimes she feeds horses or foals out of her basket filled with fruits, corn and especially apples.
The great importance of horses for the Celts and the symbol of the fertile mare giving birth to a foal and taking gentle care of it as a loving mother led the Celts to worship in her as nature and fertility in general.
Her symbols are a whip, a harness and the Key to the Doors of the Otherworld.
She is also represented by a basket filled with fruits, corn and especially apples, a cornucopia ("horn of plenty") which suggests that she could (originally) have been a fertility goddess.
Rose garlands were put around her pictures and shrines. Pigs, fruits, mares milk, and apples were offered as sacrifices in her honor.