What do we know about what the Emperor did before the Unification of Terra? He was born 8000 BC in Anatolia. This Q&A sheds a light on his birth. I don't really care about how he was born, either the reincarnation of shamans or just a freaky accident of nature, sent by a passing Old One seeing potential in humanity or whatever.
Thing is, not much is known about until the year 30k, when he is a Warlord on Terra and starts to unify mankind. So, what happened during the 38k years between his birth and when he starts unifying mankind? It is always said that he observed humanity and acted from the background. But are there any stories known about him? Special things he did, where he was during what time etc?
E.g., in the Horus Heresy novel Mechanicum, it is described that he was a knight slaying a dragon.
Dalia almost wept at the sight of the knight, a being of a fairer presence than any she had seen and one whose wondrous power was undimmed by the passage of years. The knight spurred his horse and swiftly overtook the procession, riding towards the dark scar in the earth. No sooner had he halted his mount and set his shield upon his arm than the Dragon surged from its lair, roaring with a sound louder than thunder. Dalia’s hands flew to her mouth and she cried out as she saw the Dragon’s monstrous form. In shape it was half crawling beast, half loathsome bird, its scaled head immense and its tail twenty metres long. Its terrible winged body was covered with scales, so strong and bright and smooth that they were like a knight’s armour. The light of devoured stars shone at its breast and malignant fire burned in its eyes. The warrior knight leapt to meet the Dragon, striking the monster with his lance, but its scales were so hard that the weapon broke into a thousand pieces. From the back of his rearing horse, the warrior smote the dragon with his sword, but the beast struck at him with talons like scythe blades. The warrior’s armour split open and Dalia saw blood pouring down his leg in a bright stream. The Dragon towered over its foe, dealing him fearful blows, but the knight caught them upon his shield and thrust his sword against the Dragon’s belly. The scales of the beast were like steel plates, rippling like liquid mercury as they withstood the knight’s every attack. Then the Dragon, infuriated by the thrust, lashed itself against the knight and his horse, and cast lightning upon him from its eyes. The knight’s helmet was torn from him and Dalia saw his face shine out from the battle, pale, lit by some radiance that shone from within. As he thrust at the Dragon, that radiance grew in power, so that at last it was like the light of a newborn sun.
Are there any other stations of the Emperor documented except birth and Terran Warlord at the end of Age of Strife?