Prusias ad Hypium is a Catholic titular see

Titular see

A titular see in various churches is an episcopal see of a former diocese that no longer functions, sometimes called a "dead diocese". The ordinary or hierarch of such a see may be styled a "titular bishop", "titular metropolitan", or "titular archbishop"....

. The original diocese was a suffragan of Claudiopolis

Claudiopolis

Claudiopolis is the name of a number of ancient cities named after Roman emperor Claudius, or another person bearing that name , notably:...

 in the Honoriad. It was near present-day Düzce

Düzce

Düzce is the capital city of Düzce Province in Turkey. The mayor is İsmail Bayram . The population is 125,240 which is an increase from 61.878 in 1990.- Overview :...

, Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

.

History

Memnon of Heraclea

Memnon of Heraclea

Memnon of Heraclea was a Greek historical writer, probably a native of Heraclea Pontica. He described the history of that city in a large work, known only through the Excerpta of Photius , and describing especially the various tyrants who had at times ruled Heraclea.Memnon's history encompassed...

 says that King Prusias I of Bithynia

Prusias I of Bithynia

Prusias I Cholus was a king of Bithynia...

 (237-192 B.C.) captured from the Heracleans

Heraclea Pontica

Heraclea Pontica , an ancient city on the coast of Bithynia in Asia Minor, at the mouth of the river Lycus. It was founded by the Greek city-state of Megara c.560-558 and was named after Heracles who the Greeks believed entered the underworld at a cave on the adjoining Archerusian promontory .The...

 the town of Kieros, united it to his dominions and changed its name to Prusias. Pliny

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 and Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 merely mention it, one below Mt. Hypius, the other near the River Hypius or Milan-Sou.

Bishops

Several of its bishops are known:

• George (not Hesychius, as Le Quien says), 325;
• Olympus in 451;
• Dometius in 681;
• Theophilus in 787;
• Constantine in 869;
• Leo in 879;
• St. Paul, martyred by the iconoclasts
  Iconoclasm
  Iconoclasm is the deliberate destruction of religious icons and other symbols or monuments, usually with religious or political motives. It is a frequent component of major political or religious changes...
  
  in the ninth century.

It is not known when this see disappeared; it still existed in the tenth century.