Saint Agathius, also known as Achatius or Acacius of Byzantium was a Cappadocian centurion of the imperial army. He was arrested for his faith on charges by Tribune Firmus in Perinthus, Thrace, tortured, and then brought to Byzantium (Constantinople), where he was scourged and beheaded, being made a martyr because he would not give up his Christian Faith. The date of martyrdom is traditionally May 8, when his feast is observed.