In 358 BC, Mentor, along with his brother Memnon, were hired to provide military leadership by a rebel Persian satrap, Artabazus.
Despite Mentor's capable leadership, the rebellion failed, and Artabazus, Barsine and Memnon fled to Macedon, where they were welcomed by Philip II.
With Nectanebo facing the loss of so many of his fortified towns and cities, he withdrew from Memphis towards the south, choosing not to contest his kingship in pitched battle.
After the defeat of Egypt, "Artaxerxes, seeing that Mentor the general had performed great services for him in the war against the Egyptians, advanced him over and above his other friends.
"[3] The king appointed Mentor his commander in the west in 342 BC and satrap of the Asiatic coast; he was also given a vast trove of silver.