Saint Sebastian (traditionally died January 20,Commemorated in his feast day 287) was a Christian saint and martyr, who is said to have been killed while the Roman emperor Diocletian engaged in the persecution of Christians in the 3rd century. He is commonly depicted in art and literature tied to a post and shot with arrows.
Life
|url= http://www.vam.ac.uk/images/image/4447-popup.html
|title= Reliquary of St Sebastian
|work=Metalwork
|accessdate= 2007-08-17}} Victoria and Albert Museum, London]]
The details of Sebastian's martyrdom were first elaborated by Ambrose of Milan (died 397), in his sermon (number XX) on the 118th Psalm. Ambrose, Bishop of Milan, states that Sebastian came from Milan and that he was already venerated there in the fourth century.According to Sebastian's fifth-century Acta,Acta S. Sebastiani Martyris, in J.-P. Migne, Patrologiae Cursus Completus Accurante (Paris 1845), XVII, 1021-1058; the details given here follow the abbreviated account in Jacob de Voragine
Source:
http://en.wikipedia.org/wiki/SebastiAn