Mithras

Mithras was a god, probably originating in Persia, whose worship became widespread in the Roman Empire, from the 1st to 4th centuries AD, and who was especially popular among soldiers. Mithraism was a serious competitor to Christianity, and it was completely supressed after its victory. Modern historians conjecture, however, that victorious Christianity may have taken up some elements of Mithraism, such as addressing a priest as "Father" which did not exist in early Christianity. Also, Christmas may have been Mithras' birthday before in was Jesus'.

Mithras in Gunpowder Empire
Mithras had been a member in good standing of Agrippan Rome's official pantheon for two thousand years, and the multi-deity temples maintained in every city by the Imperial government invariably included him. When visiting the office of the chief adminstrator of Polisso, Jeremy Solters noticed a large painting of Jesus and Mithras together fighting a demon. Such paintings were part of the Imperial Government's efforts to bring the Empire's various religions into greater harmony with each other. However, the Empire's Christians stubbornly continued to resist all such interpretations and depictions, to regard theirs as the only true religion and to completley reject Mithras, like all other non-Chritistian deities.