Ashoka the Great of India (304-232 BCE). He ruled for 40 years, spread Buddhism through his empire. When India gained independence from the British Empire, it adopted Ashoka's emblem for its own.
Ashoka the Great - Wikipedia, the free encyclopedia
There are surprisingly few political leaders (Augustus Caesar, Geo. Washington, Hitler, Constantine, Genghis Khan, Simon Bolivar, Napoleon, Oliver Cromwell) listed ahead of him in Michael H. Hart's "Ranking of the Most Influential Persons in History." And all of those lived later in history than Ashoka.
Religion of History's 100 Most Influential People
Augustus has to be one of the top five political leaders in history.
Geo. Washington had been a resourceful military leader, but as President he was not as significant but led a system of government that was itself a remarkable political innovation.
Genghis Khan was a tremendous military organizer but was basically a destroyer of civilizations.
Can't speak to the great kings and political leaders of China, who are probably deserving but not as well known in the West.
One or two of the Egyptian pharaohs should also be considered among the top 5 or 10 in history.