St. Ambrose, patron of bishops with backbones, ora pro nobis!

“Candid and fearless no matter how strong the opposition, Ambrose was directed to confront Maximus, the murderer of the Emperor Gratian. When Maximus refused to do penance, Ambrose excommunicated him.”

“Later he denied Emperor Theodosius [whom he had converted to Catholicism] entrance into church for his massacre of the inhabitants of Thessalonica. It was on this occasion that allusion was made to [King] David as a murderer and adulterer, and Ambrose retorted: “You have followed him in sin, now follow him in repentance.” Humbly, Theodosius accepted the penance imposed.”6

great article over at St. Peter's List