The son of a praetorian prefect, well-educated and well-connected, Ambrose was governor of Aemilia and Liguria when, in 374, he was unexpectedly acclaimed bishop of Milan, though he was not yet even baptized. He was an able administrator, a benefactor of the poor and builder of churches, an innovative liturgist who composed hymns still sung today, and an eloquent preacher who dazzled congregants with allegorizing expositions of the Old Testament that drew on Philo, Origen, and other Greek writers. Ambrose used scriptural tapestries of his own creation to persuade his hearers into following a particular course of action, a competency on display in this letter. Ambrose’s voluminous writings were an important conduit of Greek thought to the Latin West. Major works include On the Sacraments and On the Duties of the Clergy. He also wrote texts dedicated to scriptural exegesis and to the promotion of celibacy and asceticism, especially among women. His theological treatises, more synthetic than groundbreaking, challenged Homoian views of the Holy Spirit and the Incarnation.

Ambrose’s tenure as metropolitan bishop of an imperial capital brought him into considerable contact with the eastern emperor Theodosius I, who frequently resided in Milan during his visits to the West, especially from 388 to 391. Ambrose’s engagement with the emperor was confrontational. For instance, early in his stay, at a church service, Theodosius sought to take communion with the priests at the altar, as was the custom in Constantinople, but according to the church historian Sozomen (Ecclesiastical History 7.25.9), Ambrose told him to return to his seat. This was a harbinger of the complex power dynamic that would characterize the relationship between emperor and bishop in the coming years. In 390, after a general was murdered by rioters in the city of Thessalonica, troops were let loose on the city’s residents, many of whom were slaughtered.