The connection between Epona and horses was also present in the rites of Celtic kings as the goddess was thought to bestow on the king his authority to rule during a ritual.
Her worship originated with nomadic Celts in Gaul and extended throughout Continental Europe and the Roman Empire. Epona was the only Celtic deity venerated in Rome itself.
The importance of horses in Celtic culture may have contributed to her cult spreading from Gaul to Germany and eventually to Rome. For example, Celtic nobles were usually buried with their horses and saddles indicating horses were important in the after-life.
The extensive worship of Epona may also be the reason why the Celts did not eat horse meat. Epona's importance was later signified with a shrine in nearly every stable in the Roman Empire because she protected not only the horses but also those who worked with them.