'Commodus', the Son of a Roman Emperor

Comodis was not actually marcus's son at all, but the product of an affair between faustina and a gladiator. Marcus could see what was happening and openly worried that he was raising another nero. The reason why every previous roman emperor had adopted an heir was because there were simply very few blood sons to be had. There were only two emperors who died with living sons - vespasian and claudius. For every other emperor, eir adoption was not an explicit policy or even a preferred mode of succession. It was the result of inescapable circumstance.