Prusias ad Hypium
Prusias ad Hypium was a city in ancient Bithynia, and afterwards in the late Roman province of Honorias, and a bishopric that was a suffragan of Claudiopolis in Honoriade. Before its conquest by King Prusias I of Bithynia it was named Cierus or Kieros. Photius writes that it was called Kieros, from the river which flows by it.
It site was near Konuralp, Düzce Province, Turkey.History
says that King Prusias I of Bithynia captured from the Heracleans the town of Kieros, united it to his dominions and changed its name to Prusias. Pliny and Ptolemy merely mention it, one below Mt. Hypius, the other near the River Hypius.Bishops
Several of its bishops are known:
It is not known when this see disappeared; it still existed in the tenth century.
No longer the seat of a residential bishop, it remains a titular see of the Roman Catholic Church.
