Complex sentence: The Battle of the Persian Gate was a military conflict between Persian army, commanded by the satrap of Persis, Ariobarzanes, and the invading Macedonian army, commanded by Alexander the Great.
Split into simpler sentences: The Battle of the Persian Gate was a military conflict between Achaemenid Empire and Macedonia at the Persian Gates. The Persian army was commanded by the Satrap of Persis, Ariobarzanes and the invading Macedonian army was commanded by Alexander the Great.