What is "timarchus"

Timarchus or Timarch was a usurper in the Seleucid empire between 163–160 BC.

A Greek nobleman, possibly from Miletus in Asia Minor, Timarchus was a friend of the Seleucid prince Antiochus IV Epiphanes during his time as a hostage to the Roman Republic. He was appointed satrap of Media in western Iran when Antiochus IV Epiphanes became king in 175 BC, and his brother Heracleides became minister of the royal finances. The Persian part of the empire was threatened by the Parthian kingdom, and Timarchus probably spent much of his time reinforcing the defences. The Seleucid realms probably extended as far as the area of Teheran during this time.