Below is Part 3 of the brilliant new series by Epic History TV. If you haven't seen parts 1 and 2, click here. 

Alexander the Great has subjugated the Persian Empire west of the Euphrates, winning battles at the Granicus and Issus, capturing the city of Tyre and seizing control of Egypt. Now he heads east for a final showdown with Darius III, King of Kings, at Gaugamela. The great clash there will determine the fate of two empires, and win Alexander everlasting glory. But in the wake of victory, he faces the challenge of ruling over his new, sprawling empire, and dealing with usurpers and rebellion...