Mazaces succeeded Sabaces after the latter's death at the battle of Issus (333 BCE). His office lasted less than a year: when Alexander the Great invaded Egypt in late 332 BCE, Mazaces did not have enough military force to put up a resistance. Counselled by Amminapes, who knew Alexander well, Mazaces handed the country to the Macedonian without a fight, along with a treasure of 800 talents of gold. This event marked the end of the short-lived second Egyptian satrapy (343-332 BCE).
It is unknown what happened to Mazaces after this event, but Alexander assigned the role of satrap of Egypt to the GreekCleomenes of Naucratis before leaving for the East.
Mazakes may have been nominated as satrap of Mesopotamia in reward for his submission, as coins in his name and in a style similar to his Egyptian predecessor Sabakes, are found in this region, and the satrap of Mesopotamia at that time is otherwise unknown.