[7] During his advance, Alexander subdued the Uxii, a local hill people that had demanded the same tribute from him they used to receive from the Persian kings for safe passage.

Believing that he would not encounter any more enemy forces during his march, Alexander neglected to send scouts ahead of his vanguard and thus walked into Ariobarzanes' ambush.

The valley leading up to the Persian Gate is wide, allowing the Macedonian army to enter the mountains at a full march.

The road curves to the southeast (to face the rising sun) and narrows considerably at that point, making the terrain particularly treacherous, thus well suited for Ariobarzanes's purposes.

[9][10] Encyclopædia Iranica suggests defenders, as few as 700, and no more than 2000, based on the maximum number of troops likely at Ariobarzanes' disposal, but it notes that most modern historians follow Arrian, Curtius, and Diodorus unreservedly.

Alexander was forced to leave his dead behind to save the rest of his army—a great mark of disgrace to the Macedonians and to other Greeks, who valued highly the recovery and proper burial of their fallen.

Curtius and Arrian both report that prisoners of war led Alexander through the mountains to the rear of the Persian position, while a token force remained in the Macedonian camp under the command of Craterus.

Modern historian J. Prevas maintains that Ariobarzanes and his forces retreated to Persepolis, where they found the city gates closed by Tiridates, a Persian noble and guardian of the royal treasury under Darius III, who had been in secret contact with Alexander the Great.

Alexander seized the treasury of Persepolis, which at the time held the largest concentration of wealth in the world, and guaranteed himself financial independence from the Greek states.

[25] Four months later, Alexander allowed the troops to loot Persepolis, kill all its men and enslave all its women, perhaps as a way to fulfill the expectations of his army and the Greek citizens, or perhaps as a final act of vengeance towards the Persians.

[27] In May 330 BC, Alexander ordered the terrace of Persepolis, including its palaces and royal audience halls, to be burned before he left to find Darius III.