Mazares is mentioned by Herodotus as a Median general in the service of Cyrus the Great who died while putting down a revolt in Asia Minor.
Cyrus, upon hearing of the revolt, was enraged and made plans to punish the Lydians by burning Sardis to the ground.
According to Herodotus, Crœsus' recommendation was to disarm the population and enact trade laws that would turn the minds of the people to habits of luxury and pleasure: Cyrus, who was to become known for the mercy he showed to the peoples he conquered, agreed and sent his commander Mazares to put down the insurrection according to Crœsus' wishes, with instructions to return Pactyas alive for punishment.
Mazares gave chase, conquering the Ionian Greek city-states of Priene and Magnesia, capturing Pactyas after several attempts and sending him back to Cyrus for punishment.
Mazares then continued the conquest of Asia Minor, but died of unknown causes while on campaign: Pactyes being then delivered up by the Chians, Mazares presently led his army against those who had helped to besiege Tabalus, and he enslaved the people of Priene, and overran the plain of the Maeandrus, giving it up to his army to pillage, and Magnesia likewise.