|Saint Sebastian Interceding for the Plague Stricken, |
Josse Lieferinxe, 1497–1499, The Walters Art Museum
Saint Sebastian became popular in the Medieval West when he became famous for his ability to protect people from the plague. Some believe the association of the martyr shot with arrows with the plague is a reference to the Greco-Roman myth of Apollo, the archer god, who at times destroys his enemies by shooting plague-arrows from the heavens, but is also the deliverer from pestilence; thus the figure of Sebastian Christianizes this folkloric association. More likely the arrow-wounds of his martyrdom resembled the buboes that were symptoms of bubonic plague. Visually, "the arrow wounds call to God for mercy to us, as the symptoms of the unfirm call for pity from the passerby", as Joannes Molanus put it. The chronicler Paul the Deacon relates that, in 680, Rome was freed from a raging pestilence by him; this is the first of many references we have of Saint Sebastian banishing a plague.
History of the Lombards
(Bk. 6, Ch. 5)
By Paul the Deacon
In these times during the eighth indiction (A.D. 680) the moon suffered an eclipse; also an eclipse of the sun occurred at almost the same time on the fifth day before the Nones of May  about the tenth hour of the day. And presently there followed a very severe pestilence for three months, that is, in July, August and September, and so great was the multitude of those dying that even parents with their children and brothers with their sisters were placed on biers two by two and conducted to their tombs at the city of Rome. And in like manner too this pestilence also depopulated Ticinum so that all citizens fled to the mountain ranges and to other places and grass and bushes grew in the market place and throughout the streets of the city. And then it visibly appeared to many that a good and a bad angel proceeded by night through the city and as many times as, upon command of the good angel, the bad angel, who appeared to carry a hunting spear in his hand, knocked at the door of each house with the spear, so many men perished from that house on the following day. Then it was said to a certain man by revelation that the pestilence itself would not cease before an altar of St. Sebastian the martyr was placed in the church of the blessed Peter which is called "Ad Vincula." And it was done, and after the remains of St. Sebastian the martyr had been carried from the city of Rome, presently the altar was set up in the aforesaid church and the pestilence itself ceased.
 May 2nd. Pagi says that the solar eclipse occurred in 680 and the other in 681 (Giansevero).
 The historians of Pavia declare that the bishop St. Damianus begged from the Roman pontiff the remains of the holy martyr and placed them in the church of St. Peter ad Vincula (Waitz