There have been attempts by some scholars over the years, especially since the end of WWII to attempt to minimise the role and importance of Woden. Sometimes I feel this is not so much done out of legitimate and impartial scholarship but with the deliberate intention of proving an argument either through the use or misuse of evidence or the lack thereof.
An interesting book was published and translated into English in 2011 titled The Mercury-Woden Complex (original Der Merkur-Wodan Komplex) by an anonymous author called 'GardenStone'. Why he should not use his real name I do not know. It is interesting in the sense that it attempts to explore the Cult of Woden and the extent of its spread but I was rather disappointed by the author's approach. My feeling was that his intention was to 'prove' a particular viewpoint rather than to explore the issue with complete impartiality and detachment-a necessary prerequisite for a scholar. However do not let this put you off from buying the book as it contains a lot of interesting and useful information.
Tacitus in his Germania makes it very clear that Woden, who he calls 'Mercury' according to the Interpretatio Romana is the primary God of the Germanic peoples:
"As for gods, Mercury is the one they worship most, and on certain days they think it is right to propitiate him even with human victims. Hercules and Mars they appease with lawful animals. Part of the Suebi sacrifice also to Isis;........" (Germania 9.1)
Naturally the Romans compared their classical pantheon with the peoples which they encountered, especially the Teutons and Celts but we must remember that exact comparisons cannot be made.
Caesar writing in the century prior to Tacitus also refers to the Gods of the Celtic Gauls using Roman nomenclature:
"The god they worship most of all is Mercury. There are many images of him, and they say that he is the inventor of all the arts and the director of ways and journeys; they believe that he has greatest power over the pursuit of profit and matters of trade. After him they worship Apollo, Mars, Jupiter, and Minerva." (The Gallic War Book 6, 17)
It is interesting that both the Gauls and Teutons held their equivalent of 'Mercury' to be their primary God.
GardenStone rightly or wrongly is rather scathing about the Interpretatio Romana in that ordinary common people decided for themselves which classical Gods their native Teutonic or Celtic deities resembled rather than scholars. However this is a presumption on his part and one which cannot be proven. He states that between 65 to 70 inscriptions have been found where Mercury has been linked to a native deity. He points out however that none of these inscriptions refer to Woden. He is in my opinion correct in assuming that the Romans equated many other Gods with Mercury not just Woden but this does not establish that the Mercury-Woden connection is in itself not justified.
Mercury like His Greek counterpart Hermes was a God who conducted the souls of the dead to the underworld. In other words He was a psychopomp. Woden does share this very same aspect. We are all familiar of course with Woden as the leader of the Wild Hunt. Two other features which Mercury and Woden share (which GardenStone acknowledges) is that both Gods received human sacrifice and were Gods of magic.
However in the classical pantheon Jupiter/Zeus was regarded as the father of the Gods and yet Thunor who the Eddas refer to as a son of Woden is equated with Jupiter/Zeus. Quite remarkably Saxo Grammaticus (1150-1220) in his The History of the Danes Books I-IX also points out this discrepancy:
"One gathers plainly from this very nomenclature of days that the persons who were honoured by our people were not the same as those the early Romans called Jupiter and Mercury, or those whom Greece and Italy accorded all the homage of superstition. What we call Thor's or Odin's day is termed by them Jove's or Mercury's day. If we accept that Thor is Jupiter and Odin Mercury, following the change of the days' designations, then it is clear proof that Jupiter was the son of Mercury, if we abide by the assertions of our countrymen, whose common belief is that Thor was the child of Odin. As the Romans hold to the opposite opinion that Mercury was born of Jupiter, it follows that if their claim is indisputed, we must realise that Thor and Jupiter, Odin and Mercury are different personages." (Book VI)
This is a significant observation when one considers that Saxo like Snorri lived between the 12th and 13th centuries. The level of scholarship for that time must be commended. However he is overlooking one significant issue. The Scandinavians were wrong to assume that Thor was the son of Odin. This is a fairly childish way of viewing the Gods. We now know that the Cult of Woden or Odin penetrated Scandinavia well after the Cult of Thor or Thunor was established. Indeed in Norway it did not replace the Cult of Thor. The cult spread from Germany, quite possibly from the Upper Saxony/Thuringia region which some scholars such as Francis Owen (The Germanic People. Their Origin, Expansion & Culture) theorise was the centre from where the Single Grave-Corded Ware-Battle Axe culture spread from. This was of course a clearly Indo-Germanic material culture. My personal opinion is that this material culture also helped to spread the Aesir family of deities which eventually fused with the native Scandinavian Vanir.
Troy Southgate in his admirable Woden. Thoughts & Perspectives, Volume Four relates to us the tale of the spread of the Cult of Woden as initially told to us by Snorri Sturluson (1179-1241) in the Prologue to his Younger or Prose Edda. Snorri being a xtian would not or perhaps could not accept that the Gods of the Germanic peoples were actually divine entities and so he euhemerised them. In other words he claimed that they were human beings, albeit extremely clever ones who became deified over the course of time due to their achievements. The fact that both Snorri, an Icelander and Saxo, a Dane should both euhemerise the Gods in this way perhaps demonstrates that they were following a standard xtian tradition although euhemerism originated in Classical Greek times and was the invention of Euhemeros of Messene (circa 300 BCE).
I am not sure about Mr Southgate's intentions when he wrote the Foreward to his book but our Gods must never be thought of as just deified human beings. This is no basis for a religion or a folkish revival. However the story is interesting from the perspective that it may give us a clue as to how the Cult of Woden was introduced into northern Europe as part of (in my opinion) a wider material Indo-Germanic culture which had the features of the Battle Axe, single graves and Corded Ware pottery.