Ariobarzanes was appointed as the first satrap of Persis (the southern province of Fars in present-day Iran) in 335 BC by Darius III Codomannus.

Historians are surprised that Darius III appointed satrap of Persepolis and Persis; apparently, that office did not previously exist.

Ariobarzanes commanded part of the Persian Army fighting against the Macedonians at the Battle of Gaugamela in 331 BC.

Some sources indicate that the Persians were betrayed by a captured tribal chief who showed the Greeks an alternate path that allowed them to outflank Ariobarzanes in a reversal of Thermopylae.

The commander of the city's garrison had decided the outcome of the battle, and was convinced that Alexander was bound to the throne of the empire.