Saint Sebastian
Saint Sebastian was a fourth-century roman martyr who later gained a preminent position as holy defensor against the plague. Because of his faith he was sentenced to death by the Roman Emperor. Sebastian was pierced endless time by arrows, however he miracoulously survived. Made stronger by this miracolous survival, he publicly reproaced the Emperor of crime against the servants of Christ. He was eventually killed and his body was dispersed. However, a Christian matron dreamt about his location, found the body and burried him with all the honour, establishing Saint Sebastian's cult.
In the seventh century, the Saint Sebastian was accreditate with the liberation of the city of Pavia from the plague, and since then he gain the fame of intercessor against the plague. The event it is first recorded by Paul the Deacon ( circa 720 - 797 ) in the History of the Lombards, but its later re-telling in the widely read Jacobus de Voragine's Golden Legend decisively established Sebastian popularity as plague protector.
Iconography
In the Renaissance the saint is usually depicted naked or semi naked, tigh to a tree and pierced with a variable number of arrows. Sometimes he is the central subject of the artwork, however often he accompanies the Virgin or other siants.
The arrows were an ancient symbol of divine justice thrown in response to human weakness. The Greek god Apollo was known to cause death and pestilence with his dards, but was also called upon for healing and protection from epidemic diseases. Therefore, scholars have argued that the cult of Apollo was transfered on the Christian martyr Sebastian. The arrows that afflict his body, thus, symbolically identified with God's chastisement.
Sebastian's life and martyrdom also mirrors Christ's sacrifice on the cross, who aimed to redeem humanity from sins. In the words of expert Louise Marshall: Sebastian humble acceptance of his 'martyrdom by the arrows of the plague becomes a vicarious sacrifice offered up to God. Christ-like, he takes the sins of humanity upon himself and makes restitution for these sins with his own sufferings'. It could be said that by attracting on himself the plague-arrows of divine wrath, he take upon himself the punishment, sparing humanity from the disease.
Depicted alive despite the deadly wounds, the saint prompts hopeful sentiments of present and future salvation for the faithful.
Further readings on this topic
Barker Sheila, ‘The Making of a Plague Saint: Saint Sebastian’s Imagery and Cult before the Counter-Reformation’, in Franco Mormando and Thomas worcester (eds), Piety and Plague: Form Byzantium to the Baroque, Kirksville, Missouri, 2007, pp. 90-131.
Marshall Louise, 'Reading the Body of a Plague Saint: Narrative Altarpieces and Devotional Images of St. Sebastian in Renaissance Art', Reading Text and Images. Essays on Medieval and Renaissance Art and Patronage in honour of Margaret M. Manion., University of Exeter Press, 2002, pp. 237-272.
Voragine, Jacobus. The Golden Legend: Reading on Saints, 2 vols. Translated by Granger Ryan, Princeton University Press, 1993.