Arrian, a Greek writing two centuries later from the memoirs of Alexander’s generals, tells the march of Alexander the Great. This is Book 3 of the Anabasis. Book 2 left him after Issus, on the coast of what is now southern Turkey: Darius III, the Great King of Persia, had fled, the Levant was taken, and Egypt was next.

Egypt hails him as pharaoh, the old title of the kings of the Nile. He stakes Alexandria on the limestone between a lake and the sea. In the desert the oracle at Siwah, a shrine of the god Ammon, greets him as Ammon’s son. Then Gaugamela, in what is now northern Iraq: Darius has the open ground he wanted, with scythed chariots and elephants. Alexander drives the Companion cavalry, his elite horsemen, at the King. Darius runs a second time. Babylon strews flowers. Susa yields its treasure. In winter they force the Persian Gates in the mountains of Iran. Persepolis, the ceremonial capital, is burned. Bessus, a satrap — a Persian provincial governor — murders Darius on the road. Alexander covers the dead king with his cloak and hunts the killer across Iran.