Emperors Gratian, Valentinian II, and Theodosius

This entry represents the joint imperial college of the late fourth century to whom Bishop Ambrose of Milan addressed official letters: Gratian (r. 367-383), the young western emperor whom Ambrose mentored and for whom he wrote the treatise De Fide; Valentinian II (r. 375-392), Gratian's half-brother, a boy emperor whose court at Milan Ambrose repeatedly confronted, most famously in the 384 dispute over the Altar of Victory and the 385-386 basilica crisis; and Theodosius I (r. 379-395), the powerful eastern (and later sole) emperor whose public penance after the massacre at Thessalonica in 390, imposed by Ambrose, became a defining moment in the relationship between church and Roman state. Late Roman correspondence was conventionally addressed to the whole reigning imperial college even when one ruler was the true recipient, which is why these three names appear together. Through this correspondence Ambrose helped establish the principle that even emperors stood under the moral authority of the church.