Selymbria, a titular see in Thracia Prima, suffragan of Heraclea. Selymbria, or Selybria, the city of Selys on the Propontis, was a colony of the Megarians founded before Byzantium. It was the native place of Prodicus, a disciple of Hippocrates; there Xenophon met Medosades, the envoy of Seuthes, whose army later encamped near by. In 410 B.C. Alcibiades, who commanded in the Propontis for the Athenians, was not allowed to enter the town, but the inhabitants paid him a sum of money; somewhat later he captured it by treason and left a garrison there. In 351 B.C., Selymbria was an ally of the Athenians and in 343 was perhaps attacked by Philip. In honor of Eudoxia, wife of the Emperor Arcadius, it was called Eudoxiopolis, still its official name in the seventh century, doubtless together with the older one which finally survived. In 805 it was pillaged by the Bulgarian king, Kroum. Michael III constructed a fortress the ruins of which are still existing there. The town is often mentioned by the Byzantine historians; in 1096 Godfrey of Bouillon ravaged the country. Cantacuzenus celebrated the marriage of his daughter Theodora and the sultan Orkhan with great pomp at Selymbria. The Turks captured the town in 1453. It is now Silivri, chief town of a caza in the vilayet of Adrianopolis, containing 8000 inhabitants, Turks and Greeks, mostly farmers or fishermen.
In the tenth century it became an autocephalous archbishopric and under Marcus Comnenus a metropolis without suffragan sees. It would be easy, therefore, to add to the list of its bishops given by Le Quienin “Oriens christianus”, I, 1137. The oldest known is Theophilus transferred from Apamea (Socrates, “Hist. eccl.”, VII, xxxvi). We may mention before the Schism: Romanus, 448, 451; Sergius, 80; George, 692 Epiphanius, author of a lost work against the Iconoclasts. Simeon assisted in 879 at the Council of Constantinople which reestablished Photius. Under Michael Palwologus, the Metropolitan of Selymbria, whose name is unknown, was one of the prelates who signed a letter to the pope on the union of the Churches. In 1347 Methodius was one of the signatories at the Council of Constantinople which deposed the patriarch John Calecas, the adversary of the Palamites. The date of Ignatius, who wrote a “Life of Constantine and Helena”, is unknown, perhaps about 1431. Among the bishops omitted by Le Quien must be mentioned Philotheus, who lived about 1365, the author of the panegyric on St. Agathonicus, a martyr of Nicomedia who suffered at Selymbria under Maximian, and of the panegyric on Saint (?) Macarius, a monk of Constantinople towards the end of the thirteenth century (Krumbacher, “Gesch. der byzant. Litteratur”, Munich, 1897, 205).