Worship of Odin dates back to early Germanic paganism. The most compelling evidence of this historical connection is found in the accounts of Tacitus and Julius Caesar, who describe the Germanic pagans participating in a cult of "Mercury" dedicated to a figure matching Odin in both attributes and areas of patronage.^[10]

Thus, it is theorized that Scandinavian Óðinn emerged from Proto-Norse *Wōdin during the Migration period (especially 100 B.C.E. - 600 C.E.). The archaeological record bolsters this conjecture, as Vendel artwork (bracteates, image stones) depicts scenes that can be aligned with the High Medieval Norse mythological texts. Further, the context of the new elites emerging in this period aligns with Snorri's (euhemeristic) tale of the indigenous Vanir who were eventually replaced by the Aesir, understood as intruders from the continent.^[11]

Additionally, parallels between Odin and Celtic Lugus have often been pointed out: both are intellectual gods, commanding magic and poetry. Both have ravens and a spear as their attributes, and both are one-eyed. A likely context of the diffusion of elements of Celtic ritual into Germanic culture is that of the Chatti, who lived at the Celtic-Germanic boundary in Hesse during the final centuries before the Common Era. However, it must be remembered that Odin in his Proto-Germanic form was not the chief god, but that he only gradually replaced Tyr during the Migration period.

also: Helene A. Guerber's 1909 book, "Myths of the Norsemen," and H.R. Ellis Davidson's 1964 book, "Gods and Myths of Northern Europe."