Philip or Philip the Arabian (Marcus Julius Philippus), 204?–249, Roman emperor (244–49). He served under Gordian III against the Persians, instigated the assassination of the emperor, and concluded a peace with Persia. The millennium of Rome was celebrated by him with the splendor of secular games in the Circus Maximus. Philip sent Decius to the Danube to quell a mutiny, but when the troops hailed Decius as emperor, he marched at their head upon Italy. Philip met them near Verona and was slain.