Apollonia (modern Gölyazı/Bursa) was city in Bithynia situated on a lake of the same name. Apollonia appears in history in the 8th-9th century as a strong fortress; it was a refuge for the deposed emperor Tiberios II and a place of exile for Theodore of Stoudios. It was briefly taken by the Turks in 1093, recaptured by Alexios I, then attacked again in 1113. It then remained Byzantine until the early 14th century, except for a Latin occupation in 1204-1205. Apollonia was a suffragan bishopric of Nicomedia; it derived strength from its protected location and its walls, whose style indicates construction in the 7th/8th century with rebuilding in the 12th century. An adjacent island contains a church, apparently of the 9th century, built on a novel variation of the inscribed cross plan. It was probably the monastery from which Arsenios Autoreianos was called to the patriarchate in 1254.
Section under construction
Oxford Dictionary of Byzantium