Baring-Gould’s sources: Roman and other Latin Martyrologies. Datius, Dacius, or Dasius, is spoken of by Procopius Cassidorus, whose letter to S. Datius is extant, and by S. Gregory the Great, who relates the incident of his reduction of the evil spirits to silence, narrated in the text, in his Dialogues, lib. iii., c. 4.
S. Datius ruled the see of Milan [a bishop’s “see” is his diocese, named from his seat (Latin sedes)] in a stormy time, when Italy was over-run with the Goths [Germanic peoples who invaded the Roman Empire, many of them Arian Christians]. When Milan was threatened, S. Datius implored Belisarius to come to its protection, or send troops to defend the city. Belisarius was then at Rome, and S. Datius made the journey to Rome, on purpose to urge upon him, in person, the protection of the city. Belisarius, though hard pressed through the deficiency of supplies afforded him by the Emperor Justinian [Byzantine emperor 527–565], detached a body of men to the defence of the Milanese, and for a time Milan was thought to be safe. Soon, however, a large army of Goths and Burgundians swooped down upon it and besieged it. Belisarius, seeing the danger to which the city was exposed, sent troops under his generals, Martin and Uliaris, to the succour. But they, through timidity, did not venture to attack the Goths. In the city famine prevailed to such an extent, that as S. Datius relates in his Annals, an unfortunate mother roasted and ate her infant, that being the first morsel she had eaten since her confinement. The city was surrendered, but the terms of surrender were not kept. It was given up to plunder, and the streets ran with the blood of the butchered citizens. What became of the Archbishop is not known; some assert that he was taken captive to Ravenna, but was liberated at the intercession of his friend Cassiodorus.
The Arian [followers of Arius, who taught that the Son is a created being, not fully God] King, Totila, drove S. Datius from his see, and he escaped to Constantinople. On his way occurred that incident recorded by S. Gregory the Great, by which he is chiefly known. Arriving at Corinth, and looking about for a large house, which would lodge him and his companions, he saw a mansion, which seemed exactly suited to his purpose, and was apparently unoccupied. Having instituted inquiries, he was told that the house was haunted, and that it was impossible for any man to spend the night in it. "Ghost and devil will not scare a servant of God!" said S. Datius, and he ordered beds to be made in the haunted house. He said his prayers as usual, and then retired to rest. About midnight he was aroused by a hideous rout, like the braying of asses, the grunting of swine, the squeaking of rats, and the hissing of serpents. Then Datius, raising himself in bed, shouted, "Oh, Satan! thou who saidst in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will be like the most High! (Isa. xiv. 13, 14.) Well done, I say, Satan. Thou, who wouldst be like God, art reduced to bray like a jackass, and grunt like a hog." Instantly there was dead silence, and S. Datius was no more troubled with unearthly noises.
