Sebasteia
SEBASTEIA (Σεβάστεια), a town in the south of Pontus, on the north bank of the Upper Halys. As it was near the frontier, Pliny (Plin. Nat. 6.3) regards it as not belonging to Pontus, but to Colopene in Cappadocia. (Ptol. 5.6.10; Hierocl. p. 702; It. Ant. pp. 204, 205.) The town existed as a small place before the dominion of the Romans in those parts, but its ancient name is unknown. Pompey increased the town, and gave it the name of Megalopolis (Strab. 12. p. 560). The name Sebastia must have been given to it before the time of Pliny, he being the first to use it. During the imperial period it appears to have risen to considerable importance, so that in the later division of the Empire it was made the capital of Armenia Minor. The identity of Sebastia with the modern Siwas is established partly by the resemblance of the names, and partlyby the agreement of the site of Siwas with the description of Gregory of Nyssa, who states that the town was situated in the valley of the Halys. A small stream, moreover, flowed through the town, and fell into a neighbouring lake, which communicated with the Halys (Orat. I. in XL. Mart. p. 501, Orat. II. p. 510; comp. Basil. M. Epist. viii.). In the time of the Byzantine empire Sebasteia is mentioned as a large and flourishing town of Cappadocia (Nicet. Ann. p. 76; Ducas, p. 31); while Stephanus B. (s. v.) and some ecclesiastical writers refer it to Armenia. (Sozom. Hist. Eccl. 4.24; Theodoret. Hist. Eccl. 2.24.) In the Itinerary its name appears in the form of Sevastia, and in Abulfeda it is actually written Siwas. The emperor Justinian restored its decayed walls. (Procop. de Aed. 3.4.) The town of Siwas is still large and populous, and in its vicinity some, though not very important, remains of antiquity are seen. (Fontanier, Voyages en Orient. 1. p. 179, foil.)
[L.S]This is almost certainly the same as Megalopolis, which Pompey founded (64 B.C.) in the southernmost region of Mithridates' former kingdom. Parts of the city's large territory were transferred by Antony to Comana Pontica and to the Galatian chieftain Ateporix. At a later stage Megalopolis belonged to Pythodoris of Pontus. The name Sebasteia is likely to commemorate a refoundation when the city was annexed to Galatia between 2-1 B.C. and A.D. 1-2. Sebasteia had metropolitan status from the time of Verus. In Diocletian's reorganization of the provinces it became metropolis of Armenia Prima.
Sebasteia evidently lay at or near modern Sivas on the Kizil Irmak (Halys fl.). Excavation on the citadel of Topraktepe in Sivas has revealed nothing Roman, and the exact site remains to be discovered.
D. R. WILSON