The tragic boy emperor, Philip II

Philip II (Latin: Marcus Julius Severus Philippus; 237 – 249CE), also known as Philip the Younger, was the son and heir of the Roman Emperor Philip the Arab by his wife Marcia Otacilia Severa. When his father became emperor in 244, young Philip was appointed caesar at the age of only seven-years-old. In 247, he became consul, and was later elevated by his father to the rank of augustus and co-ruler.  Although ancient historians claim both Philip the Arab and his son were killed in battle by Decius.  

Decius was a distinguished senator who had served as suffect consul in 232, had been governor of Moesia and Germania Inferior soon afterwards, served as governor of Hispania Tarraconensis between 235 and 238, and was urban prefect of Rome during the early reign of Emperor Philip the Arab. In 248 or 249 Decius was sent to quell the revolt of Pacatianus and his troops in Moesia and Pannonia, a rebellion seen by some modern historians as emerging Balkan separatism.  After the collapse of the revolt, Decius let the troops proclaim him emperor. Philip advanced against him and was killed at Verona, Italy, in September 249. The Senate then recognized Decius as emperor, giving him the attribute Traianus in reference to Emperor Trajan, an emperor considered the ultimate example of a ruler at the time. According to the Byzantine historian Zosimus, Decius was clothed in purple and forced to undertake the [burdens of] government, despite his reluctance and unwillingness.  

Modern scholars do not think Philip II was with his father in Verona and suggest that when news of his father's death and the proclamation of Decius as the new emperor reached Rome, the Praetorian Guard murdered the 12-years-old. 

Bust of Philip II at the archaeological museum in Venice, Italy, courtesy of Wikimedia Commons contributor Architas.

Previously crushed portrait of Philip the Younger from Asia Minor, 235 CE, bronze, at the J. Paul Getty Museum (Villa)

Portrait of Philip II, 247-249 CE, from the Chiragan Roman Villa, now in the Musée Saint-Raymond, image courtesy of Wikimedia Commons contributor Daniel Martin.