Several saints and martyrs occur who bear this name.
1. One is usually associated with a martyr named Bacchus, like himself a native of Rome. It is related that they were accused of being Christians, and exiled by the emperor Maximian. When nothing could induce them to sacrifice to idols, Bacchus was tortured to death and his body thrown to wild beasts, who, however, would not harm it. Sergius was then taken to Rosaph, in Syria, and tortured, but comforted by an apparition of Bacchus, while his wounds were healed by an angel. He was beheaded in 290; and the emperor Justinian is credited with having changed the name of Rosaph to Sergiopolis, while the martyr's relics were preserved in the church of that town. Oct. 7 was set apart for the commemoration of Sergius and Bacchus.
2. Another Sergius, whose day occurs on Jan. 23, is said to have been martyred under Diocletian; and a third was a monk in the Convent of Mar Saba, in Palestine, and, together with other monks, was attacked and slain by robbers in the year 797. His day is on March 30.
3. Sergius, surnamed the Confessor, was born at Constantinople, lived in the former half of the 9th century, and wrote De Rebus in Re Publica et Ecclesia Gestis — a history of the iconoclastic controversy from the Romish point of view, which embraced the period from Constantine Copronymus to Michael II Balbus, but is now lost. He was taken prisoner while defending the worship of images (according to some statements, in the reign of Leo the Isaurian; according to others, in that of Theophilus), deprived of his goods, and exiled; for which reason Photius termed him the Confessor. The saints' calendar of the Greek Church assigns May 13 as his day. See Ausführl. Heiligen- Lexikon nebst beigefigt. Heil.-Kalender (Cologne and Frankfort, 1719), p. 2006 sq.