Gordian III was the grandson of Gordian I and nephew of Gordian II. He was proclaimed Caesar shortly before the murder of Balbinus and Pupienus, and he succeeded them. Little is known about his reign. In 242 A.D. he embarked on a campaign against the Persian Kingdom which was so successful the Persians had to evacuate Mesopotamia. However, Gordian III died shortly after, through illness or the machinations of his Praetorian prefect and successor, Philip I.