Complex sentence: Flavius Antiochianus (flourished 3rd century) was a prominent Roman politician during the reigns of the Roman Emperors Gallienus, Claudius Gothicus, Quintillus and Aurelian, in the period referred to as the Crisis of the Third Century in the Roman Empire.
Split into simpler sentences: Flavius Antiochianus (flourished 3rd century) was a prominent Roman Politician that lived in the reigns of the Roman Emperors Gallienus, Claudius Gothicus, Quintillus and Aurelian. He lived in the period the Crisis of the Third Century in the Roman Empire.