ARBACES, the founder of the Median empire in 876 b.c., was one of the generals of Sardanapalus, king of Assyria, and had command of the contingent from the province of Media. He conspired with Belesys, a Chaldean priest, who commanded the troops from Babylon, and having gained over several other officers of the king, they revolted. After a short contest Sardanapalus was defeated, and committed suicide. The dynasty founded by Arbaces lasted till its overthrow by Cyrus, 559 b.c. This account of the Median empire rests on the authority of Ctesias, as given in Diodorus (ii. 24, 34), and cannot be reconciled with what is stated by Herodotus, who is probably referring to another event. Arbaces, the Mede, is to be distinguished from the satrap of the same name who commanded a division of the army of· Artaxerxes in his war with his brother Cyrus.