Which singles person had the greatest impact on history?

[Patriarch of Constantinople]

The only greek influence in egypt as i see it was military. They used the classic hellenestic phalanx and heavy cav.

[KukriKhan]

I was thinking 'impact' and thought of fire, wheel, etc. But the topic is 'on history', so we're limited to about 4,000 years, yes? Maybe the tech-guys (telegraph, telephone & radio) should get a nod, since their products enabled the broader dissemination religious, political and military ideas. So: Marconi, Tesla, Bell... those guys?

Or maybe the sculpter of the Rosetta Stone.