Hypius or Hypios ( grc, Ὕπιος), also Hyppius or Hyppios (Ὕππιος), was a river of

ancient Bithynia Bithynia (; Koine Greek: , ''Bithynía'') was an ancient region, kingdom and Roman province in the northwest of Asia Minor (present-day Turkey), adjoining the Sea of Marmara, the Bosporus, and the Black Sea. It bordered Mysia to the southwest, Pa ...

, not far westward from the Sangarius River. The river itself is very small; but at its mouth it is so broad that the greater part of the fleet of

Mithridates Mithridates or Mithradates ( Old Persian 𐎷𐎡𐎰𐎼𐎭𐎠𐎫 ''Miθradāta'') is the Hellenistic form of an Iranian theophoric name, meaning "given by the Mithra". Its Modern Persian form is Mehrdad. It may refer to: Rulers *Of Cius (al ...

was enabled to take up its winter quarters in it. According to the ''

Periplus of Pseudo-Scylax The ''Periplus of Pseudo-Scylax'' is an ancient Greek periplus (περίπλους ''períplous'', 'circumnavigation') describing the sea route around the Mediterranean and Black Sea. It probably dates from the mid-4th century BC, specifically ...

'', this river formed the boundary between the territories of the Bithyni and the

Mariandyni The Mariandyni (Μαριανδυνοί or Μαρυανδυνοί) were an ancient tribe in the north-east of Bithynia. Their country was called ''Mariandynia'' (Μαριανδυνία, Stephanus of Byzantium s. v.) and Pliny speaks of a ''Sinus Ma ...

. It is identified with the modern Büyük Melen Su in Asiatic Turkey.

References

Bithynia Rivers of Turkey Düzce Province Ancient Greek geography {{Düzce-geo-stub