Good point.<quoted text> I really don't think it can be attributed to one singular person, not in the historical sense. Much like who is the "father" of the United States. That answer would depend on who you ask. Many "fathers", but that original founder is non existent.
It's said that Zoroastrianism was the first monotheistic religion.
But Hinduism, in some respects is considered monotheistic(since the "god" is said to be in all things at all times), but in practice it's often seen as polytheistic by those not Hindu. Although there are Hindu sects that are certainly monotheistic and have been for more than 4,000 years.
I tend to think most earth-centric or Pantheist beliefs are monotheistic in effect, but the focal point in practice is seen as polytheistic at times.
Like in Stregheria and Wicca, one sees numerous lists of gods that run on seemingly for page after page; yet most who believe the Old Ways will tell you that these are *different aspects* of the divine duality. A name for each aspect. When one prays for wisdom, for examle, they'll invoke Athena; when one prays to find love, they invoke Aphrodite or Venus. Two different aspects of the same goddess.