Titus Aurelius Fulvus Antoninus and Lucius Aurelius Commodus were born in Lanuvium on 31 August 161. They were the tenth and eleventh children of Marcus Aurelius, who had recently become emperor, and his wife Faustina. The first-mentioned must have been the elder of the two, because he was called Antoninus, the name which Marcus gave to his heir apparent (cf. Titus Aurelius Antoninus).
The birth of the two boys was commemorated on coins, and - if we are to believe the Historia Augusta note[Historia Augusta, "Commodus" 1.4.] - the omens were favorable. However, the elder of the two appears to have been a weak child. One of the letters of Fronto, who had been the teacher of Marcus Aurelius, mentions that Fulvus Antoninus had been ill with a cough, but was getting better.
In 165, the boy died and was -according to Roman religious beliefs- regarded as one of the immortal gods. By that time, Commodus had a new, younger brother, Annius Verus, but he died as well, and in the end, it was Commodus who succeeded to his father's throne.
Still, Fulvus was not forgotten. Several inscriptions from Thessaloniki prove that the deified boy was worshipped well into the third century; his temple appears to have been very close to the present church of Saint Demetrios. This is remarkable, because many cults for deified emperors, empresses, and princes were abolished by the emperor Maximinus Thrax (235-238). It seems that the divine Fulvus had attracted a real following outside the circle of the state cult, something extremely rare. We can only wonder how this may have happened.
According to the Greek author Herodian, Fulvus Antoninus had been nicknamed Verissimus ("most true one").note[Herodian, History of the Roman Empire 1.2.1.]