Around 445 BC he commanded the Persian army against the rebel satrap Megabyzus, being defeated as was the previous commander, Usiris. The peace was signed c. 444 BC after negotiations in which his father Artarius took part.
Artaxerxes I died in 423 BC and was succeeded by his son Xerxes II, who 55 days after was murdered by his half-brother Sogdianus, Menostanes and the eunuch Pharnacias. Sogdianus became king and named Menostanes prime minister and chief of the army. However, Sogdianus was later defeated and put to dead by Ochus, another brother, who took the throne and changed his name to Darius II. Pharnacias was executed and Menostanes committed suicide.
Apart from Ctesias there are no Classical sources on Menostanes, but he appears to be mentioned in some cuneiform tablets of the Murashu family from the Babylonian city of Nippur, where is called Manuštånu. As can be seen from the Murashu Archive, Menostanes owned large estates near Nippur. Strikingly, in 423 BC his domains passed to certain Artahšar, who was identified with Artoxares, a follower of Darius II.
- Dandamaev, M: A Political History of the Achaemenid Empire (1989).
- Donbaz, V., & Stolper, M.: "Gleanings from Muraßû Texts in the Collections of the Istanbul Archaeological Museums", in NABU 1993.
- Lendering, J.: "Megabyzus (2)", in http://www.livius.org/
- Lendering, J.: "Xerxes II and Sogdianus", in http://www.livius.org