Martin was born to pagan parents, but became Christian when he was about 10. He was born about 316 A.D. and died in A.D. 397 on November 11 (possibly November 8). Sulpicius Severus was a disciple and biographer of Martin of Tours, the author of the Vita Martini.
As a soldier in the army of Julian the Apostate, Martin asked to be discharged for his faith. Martin became a missionary in Pannonia and Illyricum, where he opposed Arianism, and accordingly, was forced out by the Arians. He went to Italy and then Gaul founding the first monastery there.
Martin was made bishop in A.D. 371.
Sources: Encyclopedia Britannica and Encyclopedia of the Middle Ages.