Which Persian commander defended the Persian Gate against Alexander?

The Persian commander who defended the Persian Gate against Alexander was Ariobarzanes. He was the Achaemenid satrap of Persis, the region around modern-day Fars in southern Iran.

In the winter of 330 BC, Ariobarzanes positioned his forces in a narrow mountain pass on Alexander’s route toward Persepolis. The terrain allowed Persian troops to ambush the Macedonians with arrows, stones, and other missiles. Alexander’s army suffered serious losses and was initially forced to retreat.

Ariobarzanes held the pass for roughly a month, giving the Persian side time to delay Alexander’s advance. Alexander eventually found a route around the defenses, reportedly with help from captives or a local guide, and attacked from the rear. The Persian position collapsed, and Ariobarzanes made a final attempt to reach Persepolis.

He is sometimes confused with Bessus, who commanded in Bactria and later betrayed Darius III, or with Mazaeus, a Persian satrap who surrendered Babylon. The defeat at the Persian Gate removed the last major obstacle before Alexander reached Persepolis.