Maximius Flavius scripsit:

Yes, Nantonos, that sounds really interesting! I have to admit Epona and her "cult" is quite foreign to me. Do you think we should start a topic on this board or discuss it on the Gods and Goddesses board, or right here in this general Military Cults topic?

Either way would work. Many known Epona inscriptions are military in nature, and many Epona representations are clustered around the Rhine-Danube limes. Others are at known postings of ex-members of the Equites Singulares Augustii (for example, one from a drill master on Hardians wall, one on Thessaloniki, a few around Budapest on the Danube bend). So, there is a strong military connection, and secondarily an ex-military civil connection (such as dedications from exploratio or beneficiari). So, there are good grounds for discussing it here.

It would be really interesting to find out more about the "roots" of the goddess, etymological and "ethnic" backgrounds and how it became a military cult. Perhaps we should just proceed with the discussion here?

Etymological is easy, its pure Gaulish. Ethnic (in terms of ethnicity of the worshipers) is harder. I don't see an especial emphasis from Gaulish units, for example (eg the Gaulish cavalry used as household cavalry in Egypt left no trace of Epona worship) but there is evidence of worship by Germanic (eg Batavian and Ubian) and Pannonian troops wherever they might be stationed.

Whether it was originally a military cult that became a more general cult due to the typical military-to-civilian (abnd back) career structure, or wether it was a (pre existing) civilian cult later adopted by the military, is something I still do not know and would love to find out.