Prior to the European Enlightenment, did any humans achieve a worldview which excluded any requirement for any supernatural agency?

I understand that some Ancient Greek philosophers may have come close: Democritus, perhaps; or Socrates (although he was only accused of believing in the wrong gods); maybe Epicurus (and his Roman follower Lucretius), but they still imagined some unknowable sentient beings in an eternal life of bliss.

(My main follow-up question might be more anthropological or archeological than historical: Is there any evidence for when Homo sapiens first invented the idea of gods? )…. Maybe I could ask: Why and how did Homo sapiens invent the idea of a single god (rather than many gods)? Was monotheism just a consequence of organised war and patriarchy or did it have some other reason?