There are many scholarly sources regarding Mithraism. Many showing that not only did it predate Christianity (though both cults reached their height at the same time) they also say it had made its way to Northern Europe before Christianity. Mithra / Mitra is an Aryan Sun God who had origins in the Vedic faith. He was a part of the Persian religion and adapted as Mithras in the Roman empire Since men and Soldiers primarily worshipped him he merged easily into Sol Invictus, the Unconquered Sun. Rome also included Jupiter/Zeus, Apollo, and Osiris to name a few under Sol Invictus. Later Christian concepts were swapped in keeping the Sol Invictus but changing him to Jesus. The Sun imagery (Halos, the Cross etc) was maintained and included in the new religion of Catholicism. Interesting note- Mitra, in the Vedas, was often referred to as Mitra-Varuna. Varuna was associated as a King/Sky God figure similar to Dyáuṣ Pitṛ́ (Vedic Sanskrit: Dyáuṣpitṛ́, द्यौष्पितृ, literally ‘Sky Father’).
