St. Ambrose lived from about A.D. 340-397. His birthplace is disputed: Trier (in today’s Germany), Arles and Lyons (in today’s France) contend for the honor. All three were important cities in the Roman Empire and Ambrose’s father was Prefect of Gaul, which encompassed these territories.

The family was Christian. While Ambrose came into the world about a generation after Constantine’s famous Edict of Milan that put an end to the persecution of Christianity and afforded it toleration in the Roman Empire, his family had been Christian for generations (as well as having responsible state roles). Ambrose’s elder sister was a religious.

Ambrose did not originally aspire to the religious life: he held a variety of civil posts, including becoming governor of the Milan area around A.D. 372. In 374, the Arian bishop of Milan died.

Ambrose was firmly orthodox in his faith, rejecting Arianism (though not individual Arians), a heresy that plagued the Church for decades, though it tended to be embraced more by higher clergy than the common faithful. Catholic theology teaches Jesus is “true God and true man,” having a complete human and a complete divine nature in one Person. The Arians denied this: they turned Jesus into some kind of intermediate creature — more than a man but, as a creature, less than God.

The tradition in Milan was for the election of its bishop and — despite the fact that he was neither deacon nor priest — Ambrose was chosen to be bishop. (Indeed, he was not even baptized, as some adults of the time deferred baptism until late in life. He was, technically, a catechumen.) He tried to evade the responsibility, even attempting to go into hiding, but eventually agreed, “Thy will be done.”

So, in a short time, St. Ambrose was baptized, ordained and consecrated a bishop. He also renounced his wealth. He then also began intense theological training, one measure of the success of which was that he was regarded as a theological authority in his day and is regarded as one of the four great Doctors of the early Church (along with Athanasius, Augustine and John Chrysostom). If you go to St. Peter’s in Rome, you can see the Chair of Peter encased in a reliquary behind the main altar. It is borne up by sculptures of those four Doctors. His theological writings were extensive and are read today, both on the proper exercise of pastoral ministry (in conjunction with morality) in the Church and the value of virginity.

One of St. Ambrose’s greatest achievements was his most famous convert: St. Augustine. Augustine, also raised in a home with a Christian mother (St. Monica), delayed and delayed committing himself to the Church and being baptized. When, as he relates in his Confessions, his final decision to receive God’s grace, it was Ambrose who instructed him in the faith and baptized him. The admiration was mutual: later, Augustine would speak of Ambrose as the model of a bishop.

Milan was among the most important cities in the Western Roman Empire. East and West were growing apart and when emperors came west, they often came to Milan. They also consulted with Ambrose, both because of his spiritual authority and reputation as well as his earlier political experience. That leads us to the painting chosen to depict this saint.

Constantine had legalized Christianity in the Roman Empire with the Edict of Milan of A.D. 313. By 381, Christianity had moved from a tolerated sect to the preferred religion of the state. But that doesn’t mean the old ways went away and, especially amid the political crumbling of the Western Roman Empire (now in an advanced state) there were those who agitated for a return to the “old ways,” i.e., paganism. Long story short, there was a civil war during this period but a “Christian” emperor — Theodosius I — ruled from 379-95, even during that conflict.

Theodosius is relevant to how our saint is depicted in art. I identified Theodosius as “Christian” in scare quotes because, technically, he was Christian and in fact did his best to stamp out the Arian heresy. But that doesn’t mean everything he did was in exemplary Christian fashion.

Legend has it that Theodosius was a man of choleric temperament. Back in Thessalonica, in Greece, a very popular charioteer was accused of pederasty, and a Roman official had him arrested, to popular discontent. A riot broke out. According to the traditional account, some Roman officials were killed, which resulted in Theodosius issuing orders to massacre Thessalonians. It’s also said he recanted but the rescission of his order did not arrive before the initial decree was carried out.

When Theodosius came to Milan, he wanted to meet with Ambrose. Ambrose did not want the Church to be used to “whitewash” the emperor with such guilt on his conscience, absent proof of repentance. The tradition says Ambrose stood in the doorway of the cathedral, blocking Theodosius’ arrival in imperial garb, refusing him admittance until he first donned penitent’s garb and did public penance. Historians today think in fact Ambrose conveniently made himself inaccessible from the city but did enforce the public penance requirement on Theodosius. In Patristic times (in comparison to Confession today), a penitent had to undertake and complete public penance for certain grave sins prior to receiving absolution from the bishop. (The “big three” sins were usually murder, adultery, and apostasy, or denial of the faith). This Theodosius did and was reconciled to the Church. But it was also a defining moment: the Church made clear even Caesar stood under God’s judgment and that crimes against life were to be atoned for, even if the work of public officials.

The claimed blockage of Theodosius’ entry to the cathedral has been the stuff of numerous painters (e.g., Rubens, van Dyck), but I chose the historically more accurate “St. Ambrose Absolving the Emperor Theodosius” by Spanish Baroque painter Juan de Valdes Leal (1622-1690). Valdes Leal lived at the same time as Bartolomé Esteban Murillo, generally regarded as the greatest Spanish Baroque painter, with whom Valdes Leal was in competition. Among Valdes Leal’s many paintings — most of which have a religious character — was a series on moments from the life of St. Ambrose.

In the painting, St. Ambrose and his accompanying ministers stand at the top of the steps, Theodosius a step below, his posture, facial expression, and hand gesture indicative of his seeking forgiveness. In keeping with the practice of public penance in the Patristic Church, the Archbishop extends his hand in absolution over the penitent. One soldier on the left draws us into the picture; another on the right, stroking his chin, learns the lesson of the accountability of even the civil power to the moral law. Both the Church and the world are on display with the cathedral and the outside visible.

If you have never viewed it, watch the Imperial Hapsburg Burial Ceremony, last performed about seven years ago. When the royal body is brought to the Capuchin Church in Vienna, the entourage knocks at the door three times. The first time all his titles are recited. The friars respond: “We do not know him.” The second time, all his academic honors are recited, to receive a similar response. The third time, he is announced as a “sinful, mortal man,” at which the doors open. That point was first made by Ambrose with Theodosius in this life. There are things of God and things of Caesar. But whatever Caesar has was first God’s, and even Caesar is not immune to his Law.