4. L. Ceionius
Commodus, who was born at Rome on the 15th of December, A. D. 130. Upon the adoption of his father by Hadrian, he passed into the gens Aelia, and was entitled L. Ceionius Aelius Aurelius Commodus.
Again, after the death of his father, he was, in pursuance of the command of Hadrian, adopted, along with M. Aurelius, by Antoninus Pius on the 25th of February, A. D. 138, and thus became L. Ceionius Aelius Aurelius Commodus Antoninus.
During the lifetime of Pius he enjoyed no peculiar distinction except the appellation filius Augusti;
in 156 he was quaestor, and in the year following consul, an honour which he enjoyed for a second time, along with his brother by adoption, in 161.
After the death of Antoninus Pius, which took place in March, 161, he was invested with the titles of Caesar
and by the favour of the new sovereign admitted to a full participation in all the imperial dignities.
At the same time, M. Aurelius transferred to him the name of Verus,
which he had himself borne up to this time, and the designation of Commodus being altogether dropped, the younger of the two Augusti was addressed as the emperor L. AURELIUS VERUS. His journey to the East; his conduct during the campaign against the Parthians; his marriage with Lucilla, the daughter of M. Aurelius; his return to Rome; the joint triumph of the two princes; their expedition into Germany, and the sudden death of Verus at Altinum in the country of the Veneti, towards the close of A. D. 169, in the 39th or 40th year of his age and the 9th of his reign, are fully detailed in the biography of M. AURELIUS, to which the reader is referred.
It may be remarked, that there is some question as to the various names enumerated above.
In opposition to the clear and explicit testimony of Spartianus, Lampridius, and Capitolinus, it has been doubted whether he was ever called Antoninus,
because it never appears upon any public monument of unquestionable authority.
But if we suppose it to have been assumed, as appears most natural, at the period of his adoption by Pius, and dropped after his elevation to the purple, the difficulty will be in a great measure removed, although it must be confessed, that the Augustan historians represent him as having received the designations of Antoninus
at the same time from M. Aurelius.
（D. C. 69.17
, &c.; Spartian. Hadrian.
23, Ael. Ver.;
Capitolin. Ver. Imp. Anton. Pius, 4, M. Aurel.
4, 5, 7, &c.)