The motif of the Dragon and the World Tree is found in the oldest stories that were written by our ancestors in the stars, and that have  come down to us today as myths.  

The purpose of those myths was to teach us universal truths through metaphors describing alchemical processes that support the spiritual  evolution of life, based on a blueprint of astrology and sacred  geometry. 

Those myths were not composed to preserve for us the history of the  human race.  But over time, the priests and scribes of various  conquering kings and emperors have cobbled together those myths to give  us a false backstory.  

That’s why I always say that the only difference between history and  mythology is that myths are true.