Originally Posted by
Zorg
I'm away from my books at the moment but in one of the early HH novels Horus relates how he has a ring that used to be the Emperor's from the ancient middle east. In Mechanicum the Emperor is shown as St George fighting the dragon.
I have a vague recollection of the Emperor, or someone else talking, about his origin and it being the shaman one. Can someone with access to the 5th ed BRB have a look at the timeline?
It is possible I'm having edition leakage here, 20+ years of background'll do that to you, but there are certainly plenty of hints and clues that the Emperor has been around since pre-history.