Gaius Avidius Cassius (c. 130 – July 175 AD) was an Egyptian Roman general and usurper. He was born in Cyrrhus, and was the son of Gaius Avidius Heliodorus, who served as praefectus or governor of Roman Egypt, and Julia Cassia Alexandra, who was related to a number of royal figures, including her descent from both Augustus and Herod the Great. He began his military career under Antoninus Pius, rising to the status of legatus legionis. He served during the Parthian war of Lucius Verus, in which he distinguished himself, for which he was elevated to the Senate, and later made Imperial legate. During the Bucolic War, he was given the extraordinary title of Rector Orientis, giving him Imperium over all of the eastern provinces of the Roman Empire.
In 175, Cassius declared himself emperor, because he had received news, from Marcus Aurelius' wife Faustina the Younger, that the Emperor Marcus Aurelius was about to die. He received broad support in the eastern provinces of Egypt, Syria, Syria Palaestina and Arabia Petraea, with Egypt being its capital. Despite his control of the vital grain production of Egypt, and his command of seven legions, he was heavily outmatched by Aurelius. While Aurelius was amassing a force to defeat Cassius, a centurion of one of Cassius' legions murdered Cassius, sending his head to Aurelius as proof.
