He grew up in Milan and became an army officer, where he distinguished himself so well that the Emperor Diocletian made him captain of the Praetorian Guard not suspecting that Sebastian was a Christian. In Rome, while fulfilling the duties of a courtier, he used his position to comfort and encourage his imprisoned fellow-Christians. By his labors and example he brought many to faith in Christ, including Chromatius, the Prefect in charge of persecuting the Roman Christians.
  Sebastian had upheld two brothers, Mark and Marcellinus, who were awaiting execution for their faith. When the day of execution came, their father Tranquillinus, who had been a pagan but through Sebastian's example had converted, presented himself to Chromatius and announced that he too was a Christian. His testimony was so powerful that the hard heart of the Prefect was melted, and he himself resolved to become a Christian.
  Caius, Bishop of Rome, gathered the new brethren (both men and women — not all of Sebasti