Aiunt quidam, quod et veri simile videtur, Commodum Antoninum, successorem illius ac filium, non esse de eo natum sed de adulterio,ac talem fabellam vulgari sermone contexunt: Faustinam quondam, Pii filiam, Marci uxorem, cum gladiatores transire vidisset, unius ex his amore succensam, cum longa aegritudine laboraret, viro de amore confessam. quod cum ad Chaldaeos Marcus rettulisset, illorum fuisse consilium, ut occiso gladiatore sanguine illius sese Faustina sublavaret atque ita cum viro concumberet. quod cum esset factum, solutum quidem amorem, natum vero Commodum gladiatorem esse, non principem, qui mille prope pugnas publice populo inspectante gladiatorias imperator exhibuit, ut in vita eius docebitur. quod quidem veri simile ex eo habetur quod tam sancti principis filius iis moribus fuit quibus nullus lanista, nullus scaenicus, nullus arenarius, nullus postremo ex omnium dedecorum ac scelerum colluvione concretus. multi autem ferunt Commodum omnino ex adulterio natum, si quidem Faustinam satis constet apud Caietam condiciones sibi et nauticas et gladiatorias elegisse. de qua cum diceretur Antonino Marco, ut eam repudiaret, si non occideret, dixisse fertur “si uxorem dimittimus, reddamus et dotem”. dos autem quid habebatur? imperium, quod ille ab socero volente Hadriano adoptatus acceperat. tantum sane valet boni principis vita sanctitas tranquillitas pietas ut eius famam nullius proximi decoloret invidia. denique Antonino, cum suos mores semper teneret neque alicuius insusurratione mutaretur, non obfuit gladiator filius, uxor infamis; deusque etiam nunc habetur, ut vobis ipsis, sacratissime imperator Diocletiane, et semper visum est et videtur, qui eum inter numina vestra non ut ceteros sed specialiter veneramini ac saepe dicitis, vos vita et clementia tales esse cupere qualis fuit Marcus, etiamsi philosophia nec Plato esse possit, si revertatur in vitam. et quidem haec breviter et congeste.
(Historia Augusta, Vita Marci Aureli Antonini 19)
Some say, and it seems plausible, that Commodus Antoninus, his son and successor, was not begotten by him, but in adultery; they embroider this assertion, moreover, with a story current among the people. On a certain occasion, it was said, Faustina, the daughter of Pius and wife of Marcus, saw some gladiators pass by, and was inflamed for love of one of them; and afterwards, when suffering from a long illness, she confessed the passion to her husband. And when Marcus reported this to the Chaldeans, it was their advice that Faustina should bathe in his blood and thus couch with her husband. 4 When this was done, the passion was indeed allayed, but their son Commodus was born a gladiator, not really a prince; for afterwards as emperor he fought almost a thousand gladiatorial bouts before the eyes of the people, as shall be related in his life. This story is considered plausible, as a matter of fact, for the reason that the son of so virtuous a prince had habits worse than any trainer of gladiators, any play-actor, any fighter in the arena, anything brought into existence from the offscourings of all dishonour and crime. Many writers, however, state that Commodus was really begotten in adultery, since it is generally known that Faustina, while at Caieta, used to choose out lovers from among the sailors and gladiators. When Marcus Antoninus was told about this, that he might divorce, if not kill her, he is reported to have said “If we send our wife away, we must also return her dowry”. And what was her dowry? The Empire, which, after he had been adopted at the wish of Hadrian, he had inherited from his father-in-law Pius. But truly such is the power of the life, the holiness, the serenity, and the righteousness of a good emperor that not even the scorn felt for his kin can sully his own good name. For since Antoninus held ever to his moral code and was moved by no man’s whispered machinations, men thought no less of him because his son was a gladiator, his wife infamous. Even now he is called a god, which ever has seemed and even now seems right to you, most venerable Emperor Diocletian, who worship him among your divinities, not as you worship the others, but as one apart, and who often say that you desire, in life and gentleness, to be such a one as Marcus, even though, as far as philosophy is concerned, Plato himself, were he to return to life, could not be such a philosopher. So much, then, for these matters, told briefly and concisely. (tr. David Magie)