In your opinion, who is the most influential figure throughout history?

Socrates, Plato, and Aristotle. Every modern political and societal argument can be traced back to them. The roles, rights, motivations, and duties of the individual versus the obligation to mankind and society are at the core of all our modern political debates as well as our historical debates, and those concepts were first fully articulated by them. If you want to find ground zero, start with those three.