Basilinopolis or Basilinoupolis (Greek: Βασιλινούπολις) was a town in Bithynia Prima (civil Diocese of Pontus), which obtained the rank of a city under, or perhaps shortly before, Roman Emperor Julian the Apostate, whose mother was Basilina.
[2] Modern scholars tentatively identify its site near Yalakdere in Kocaeli Province.
At the Council of Chalcedon (451), the Metropolitans of Nicomedia and Nicaea were in sharp dispute about jurisdiction over the see of Basilinopolis.
[6] The see does not figure in a Notitia episcopatuum of the Ecumenical Patriarchate of Constantinople after the 15th century, probably indicating that the city was destroyed in the Osmanli conquest.
[7] Historically documented bishops were: The diocese was nominally restored in no later than the 17th century as Latin titular bishopric of Basilinopolis (Latin; adjective Basilinopolitanus) or Basilinopoli (Curiate Italian).