Ochus, better known by his dynastic name of Artaxerxes III was King of Kings of the Achaemenid Empire from 358 to 338 BC. He was the son and successor of Artaxerxes II and his mother was Stateira.
Before ascending the throne Artaxerxes was a satrap and commander of his father's army. Artaxerxes came to power after one of his brothers was executed, another committed suicide, the last murdered and his father, Artaxerxes II died. Soon after becoming king, Artaxerxes murdered all of the royal family to secure his place as king. He started two major campaigns against Egypt. The first campaign failed, and was followed up by rebellions throughout the western part of his empire. In 343 BC, Artaxerxes defeated Nectanebo II, the Pharaoh of Egypt, driving him from Egypt, stopping a revolt in Phoenicia on the way.
In Artaxerxes' later years, Philip II of Macedon's power was increasing in Greece, where he tried to convince the Greeks to revolt against the Achaemenid Empire. His activities were opposed by Artaxerxes, and with his support, the city of Perinthus resisted a Macedonian siege.