Gaius Avidius Cassius vs Hydarnes the Elder

Gaius Avidius Cassius, as governor of Syria, was dispatched to Egypt to suppress the Bucolic revolt. He defeated the rebel forces, restoring Roman authority and securing the grain supply for Rome.

Upon hearing a false report of Marcus Aurelius's death, Avidius Cassius was proclaimed emperor by his legions in Syria. He accepted the title and took control of the eastern provinces, including Egypt, initiating a brief rebellion.

After a reign of three months, Avidius Cassius was assassinated by a centurion. His death ended the rebellion, and the Senate condemned his memory. Marcus Aurelius, however, spared Cassius's family and destroyed his correspondence to avoid further conflict.

Hydarnes was one of the seven Persian nobles who conspired to overthrow Gaumata, the Magian usurper who had seized the throne after Cambyses II's death. He participated in the assassination of Gaumata, paving the way for Darius I to become king.

Darius I appointed Hydarnes as governor of the central satrapies of the Achaemenid Empire, a region encompassing Media and surrounding territories. He administered this key area, ensuring loyalty and collecting tribute for the crown.

Hydarnes commanded the elite Persian infantry unit known as the Immortals during the Second Persian invasion of Greece. He led them at the Battle of Thermopylae, where they outflanked the Greek position via the Anopaia path, leading to the Greek defeat.