Trajan Decius, July 249 - First Half of June 251 A.D.
Trajan Decius, a general under Philip I, successfully crushed the revolt of Pacatian. His troops forced him to assume the imperial dignity and although he still protested his loyalty, Philip advanced against him. Decius was victorious and Philip was killed. The Senate then recognized Decius as Emperor, giving him the attribute Traianus as a reference to that good emperor. As the Byzantine historian Zosimus later noted: "Decius was therefore clothed in purple and forced to undertake the government, despite his reluctance and unwillingness." Decius spent the rest of his short reign combating barbarians. Sometime in the first two weeks of June 251, Trajan Decius and his son Herennius Etruscus became the first Roman emperors to die in battle against a foreign enemy. Herennius died at his father's side, struck by an arrow. Decius survived the initial confrontation, only to be slain with the rest of the army before the end of the day.