Julius Caesar (100-44 BCE) often appears as a flawed genius. A genius, he dominated his generation. Flawed, he was murdered for the way in which he did so. Caesar changed Rome, destroying the centuries-old Republican form of Roman government based on annually elected magistrates. He also changed the shape of Europe by attaching France to the Mediterranean world. It is not at all clear whether the failing government of Rome in the 1st century BCE would have accomplished any such thing on its own. The conquest of Gaul required the vision of a man operating outside the bounds of the Roman constitution, and the skill of one of history's greatest military minds.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/2748/caesar-the-flawed-genius/.