Gaius Julius Priscus
Priscus was born in the Roman province of Syria, possibly in Damascus, son of a Julius Marinus a local Roman citizen, possibly of some importance. The name of his mother is unknown, but his brother was Marcus Julius Philippus, later the Roman Emperor known as Philip the Arab. Priscus was probably older than Philip, since the latter's political career was pushed by his own influence. According to several inscriptions, Priscus was prefect of the province of Mesopotamia, procurator of Macedonia, second in command to Egypt's governor and held judicial responsibilities in Alexandria. Priscus became a member of the Praetorian Guard around 242 during Gordian III Persian campaign, and, when Timesitheus – the praetorian prefect – died in 243, he convinced the young emperor to substitute him with his own brother Philip. For a year, Priscus and Philip served as de facto regents of Gordian III.
When Gordian was killed by mutinous soldiers in 244, Philippus became the new emperor. As his brother and trusted ally, Priscus remained in the East, while Philip travelled to Rome. Priscus held supreme power in the Eastern provinces and his referred in inscriptions as rector Orientis. His rule was severe and oppressive. Following his brother's directives, Priscus collected heavy taxes that eventually led to rebellion and the uprising of Jotapianus, one of the four usurpers reported for Philip's reign. Apparently, Priscus managed to control this rebellion. Nothing is known on Priscus after the outbreak of Jotapianus' revolt and the facts surrounding his death are lost to history.