In c. 370, Justina became the second wife of Valentinian I. According to Socrates of Constantinople: "Justina being thus bereft of her father, still continued a virgin. Some time after she became known to Severa, wife of the emperor Valentinian, and had frequent dialogue with the empress, until their intimacy at length grew to such an extent that they were accustomed to bathe together. When Severa saw Justina in the bath she was greatly struck with the beauty of the virgin, and spoke of her to the emperor; saying that the daughter of Justus was so lovely a creature, and possessed of such symmetry of form, that she herself, though a woman, was altogether charmed with her. The emperor, treasuring this description by his wife in his own mind, considered with himself how he could espouse Justina, without repudiating Severa, as she had borne him Gratian, whom he had created Augustus a little while before. He accordingly framed a law, and caused it to be published throughout all the cities, by which any man was permitted to have two lawful wives."