Bithynia (; ) was an ancient

region In geography, regions, otherwise referred to as areas, zones, lands or territories, are portions of the Earth's surface that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and ...

, kingdom and

Roman province The Roman provinces (, pl. ) were the administrative regions of Ancient Rome outside Roman Italy that were controlled by the Romans under the Roman Republic and later the Roman Empire. Each province was ruled by a Roman appointed as Roman g ...

in the northwest of

Asia Minor Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

(present-day

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

), adjoining the

Sea of Marmara The Sea of Marmara, also known as the Sea of Marmora or the Marmara Sea, is a small inland sea entirely within the borders of Turkey. It links the Black Sea and the Aegean Sea via the Bosporus and Dardanelles straits, separating Turkey's E ...

, the

Bosporus The Bosporus or Bosphorus Strait ( ; , colloquially ) is a natural strait and an internationally significant waterway located in Istanbul, Turkey. The Bosporus connects the Black Sea to the Sea of Marmara and forms one of the continental bo ...

, and the

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

. It bordered

Mysia Mysia (UK , US or ; ; ; ) was a region in the northwest of ancient Asia Minor (Anatolia, Asian part of modern Turkey). It was located on the south coast of the Sea of Marmara. It was bounded by Bithynia on the east, Phrygia on the southeast, Lyd ...

to the southwest,

Paphlagonia Paphlagonia (; , modern translit. ''Paflagonía''; ) was an ancient region on the Black Sea coast of north-central Anatolia, situated between Bithynia to the west and Pontus (region), Pontus to the east, and separated from Phrygia (later, Galatia ...

to the northeast along the Pontic coast, and

Phrygia In classical antiquity, Phrygia ( ; , ''Phrygía'') was a kingdom in the west-central part of Anatolia, in what is now Asian Turkey, centered on the Sangarios River. Stories of the heroic age of Greek mythology tell of several legendary Ph ...

to the southeast towards the interior of Asia Minor.

Hellenistic In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the R ...

Bithynia was an independent kingdom from the 4th century BC. Its capital

Nicomedia Nicomedia (; , ''Nikomedeia''; modern İzmit) was an ancient Greece, ancient Greek city located in what is now Turkey. In 286, Nicomedia became the eastern and most senior capital city of the Roman Empire (chosen by the emperor Diocletian who rul ...

was rebuilt on the site of ancient Astacus in 264 BC by

Nicomedes I of Bithynia Nicomedes I (; lived c. 300 BC – c. 255 BC, reigned 278 BC – c. 255 BC), second king of Bithynia, was the eldest son of Zipoetes I, whom he succeeded on the throne in 278 BC. Life He began his reign by killing two of his brothers, but ...

. Bithynia was bequeathed to the

Roman Republic The Roman Republic ( ) was the era of Ancient Rome, classical Roman civilisation beginning with Overthrow of the Roman monarchy, the overthrow of the Roman Kingdom (traditionally dated to 509 BC) and ending in 27 BC with the establis ...

in 74 BC, and became united with the Pontus region as the province of Bithynia and Pontus. In the 7th century it was incorporated into the Byzantine Opsikion theme. It became a border region to the

Seljuk Empire The Seljuk Empire, or the Great Seljuk Empire, was a High Middle Ages, high medieval, culturally Turco-Persian tradition, Turco-Persian, Sunni Islam, Sunni Muslim empire, established and ruled by the Qiniq (tribe), Qïnïq branch of Oghuz Turks. ...

in the 13th century, and was eventually conquered by the

Ottoman Turks The Ottoman Turks () were a Turkic peoples, Turkic ethnic group in Anatolia. Originally from Central Asia, they migrated to Anatolia in the 13th century and founded the Ottoman Empire, in which they remained socio-politically dominant for the e ...

between 1325 and 1333.

Description

Several major cities sat on the fertile shores of the Propontis (which is now known as

, Chalcedon, Cius and Apamea. Bithynia also contained

Nicaea Nicaea (also spelled Nicæa or Nicea, ; ), also known as Nikaia (, Attic: , Koine: ), was an ancient Greek city in the north-western Anatolian region of Bithynia. It was the site of the First and Second Councils of Nicaea (the first and seve ...

, noted for being the birthplace of the

Nicene Creed The Nicene Creed, also called the Creed of Constantinople, is the defining statement of belief of Nicene Christianity and in those Christian denominations that adhere to it. The original Nicene Creed was first adopted at the First Council of N ...

. According to

Strabo Strabo''Strabo'' (meaning "squinty", as in strabismus) was a term employed by the Romans for anyone whose eyes were distorted or deformed. The father of Pompey was called "Gnaeus Pompeius Strabo, Pompeius Strabo". A native of Sicily so clear-si ...

, Bithynia was bounded on the east by the river Sangarius (modern Sakarya river), but the more commonly received division extended it to the Parthenius, which separated it from

, thus comprising the district inhabited by the Mariandyni. On the west and southwest it was separated from

by the river Rhyndacus and on the south it adjoined

and Galatia. It is occupied by mountains and forests, but has valleys and coastal districts of great fertility. The most important mountain range is the (so-called) "Mysian" Olympus (), which towers above

Bursa Bursa () is a city in northwestern Turkey and the administrative center of Bursa Province. The fourth-most populous city in Turkey and second-most populous in the Marmara Region, Bursa is one of the industrial centers of the country. Most of ...

and is clearly visible as far away as

Istanbul Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics ...

(). Its summits are covered with snow for a great part of the year. East of this the range extends for more than , from the Sakarya to

. Both of these ranges are part of the border of mountains which bound the great tableland of

Anatolia Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

. The broad tract which projects towards the west as far as the shores of the Bosporus, though hilly and covered with forests—the Turkish ''Ağaç Denizi'', or "The sea of Trees"—is not traversed by any mountain chain. The west coast is indented by two deep inlets, the northernmost, the Gulf of İzmit (ancient Gulf of Astacus), penetrating between into the interior as far as

İzmit İzmit () is a municipality and the capital Districts of Turkey, district of Kocaeli Province, Turkey. Its area is 480 km2, and its population is 376,056 (2022). The capital of Kocaeli Province, it is located at the Gulf of İzmit in the Sea ...

(ancient

), separated by an isthmus of only about from the

; and the Gulf of Mudanya or Gemlik (Gulf of Cius), about long. At its extremity is situated the small town of Gemlik (ancient Cius) at the mouth of a valley, communicating with the lake of Iznik, on which was situated

. The principal rivers are the Sangarios which traverses the province from south to north; the Rhyndacus, which separated it from Mysia; and the Billaeus (Filyos), which rises in the Aladağ, about from the sea, and after flowing by modern Bolu (ancient Bithynion-Claudiopolis) falls into the Euxine, close to the ruins of the ancient Tium, about northeast of Heraclea Pontica (the modern Karadeniz Ereğli), having a course of more than . The Parthenius (modern Bartın), the eastern boundary of the province, is a much less considerable stream. The valleys towards the Black Sea abound in fruit trees of all kinds, such as oranges, while the valley of the Sangarius and the plains near Bursa and Iznik (Nicaea) are fertile and well cultivated. Extensive plantations of mulberry trees supply the silk for which Bursa has long been celebrated, and which is manufactured there on a large scale.

History

Iron Age

Bithynia is named for the

Thracian The Thracians (; ; ) were an Indo-European speaking people who inhabited large parts of Southeast Europe in ancient history.. "The Thracians were an Indo-European people who occupied the area that today is shared between north-eastern Greece, ...

tribe of the ''

Bithyni The Bithyni (; ; ) were a Thracian tribe who lived in Bithynia. History The Bithyni originally lived in the area of the lower Strymon river, due to which the ancient Greeks claimed that they were originally called the Strymoni (; ). Around , ...

'', mentioned by

Herodotus Herodotus (; BC) was a Greek historian and geographer from the Greek city of Halicarnassus (now Bodrum, Turkey), under Persian control in the 5th century BC, and a later citizen of Thurii in modern Calabria, Italy. He wrote the '' Histori ...

(VII.75) alongside the '' Thyni''. The " Thraco-Phrygian" migration from the Balkans to Asia Minor would have taken place at some point following the

Bronze Age collapse The Late Bronze Age collapse was a period of societal collapse in the Mediterranean basin during the 12th century BC. It is thought to have affected much of the Eastern Mediterranean and Near East, in particular Egypt, Anatolia, the Aege ...

or during the early Iron Age. The Thyni and Bithyni appear to have settled simultaneously in the adjoining parts of Asia, where they expelled or subdued the

Mysians Mysians (; , ''Mysoí'') were the inhabitants of Mysia, a region in northwestern Asia Minor. Origins according to ancient authors Their first mention is by Homer, in his list of Troy, Trojans allies in the Iliad, and according to whom the Mysia ...

Caucones The Caucones ( ''Kaukônes'') were an autochthonous tribe of Anatolia (modern-day Turkey), who later migrated to parts of the Greek mainland ( Arcadia, Triphylian Pylos and Elis). Origin and early history The phonology of the name Caucone ...

and other minor tribes, the Mariandyni maintaining themselves in the northeast. Herodotus mentions the Thyni and Bithyni as settling side by side. No trace of their original language has been preserved, but Herodotus describes them as related to the tribes of Thracian extraction. Later the

Greeks Greeks or Hellenes (; , ) are an ethnic group and nation native to Greece, Greek Cypriots, Cyprus, Greeks in Albania, southern Albania, Greeks in Turkey#History, Anatolia, parts of Greeks in Italy, Italy and Egyptian Greeks, Egypt, and to a l ...

established on the coast the colonies of Cius (modern Gemlik); Chalcedon (modern

Kadıköy Kadıköy () is a municipality and Districts of Turkey, district on the Asian side of Istanbul Province, Istanbul Province, Turkey. Its area is 25 km2, and its population is 467,919 (2023). It is a large and populous area in the Asian si ...

), at the entrance of the Bosporus, nearly opposite

Byzantium Byzantium () or Byzantion () was an ancient Greek city in classical antiquity that became known as Constantinople in late antiquity and Istanbul today. The Greek name ''Byzantion'' and its Latinization ''Byzantium'' continued to be used as a n ...

(modern

) and Heraclea Pontica (modern Karadeniz Ereğli), on the Euxine, about east of the Bosporus. The Bithynians were incorporated by king Croesus within the

Lydia Lydia (; ) was an Iron Age Monarchy, kingdom situated in western Anatolia, in modern-day Turkey. Later, it became an important province of the Achaemenid Empire and then the Roman Empire. Its capital was Sardis. At some point before 800 BC, ...

n monarchy, with which they fell under the dominion of

Persia Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

(546 BC), and were included in the satrapy of

, which comprised all the countries up to the Hellespont and Bosporus.

Kingdom of Bithynia

Even before the conquest by

Alexander Alexander () is a male name of Greek origin. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here ar ...

, the Bithynians appear to have asserted their independence, and successfully maintained it under two native princes, Bas and Zipoites, the latter of whom assumed the title of king (''

basileus ''Basileus'' () is a Greek term and title that has signified various types of monarchs throughout history. In the English language, English-speaking world, it is perhaps most widely understood to mean , referring to either a or an . The title ...

'') in 297 BC. His son and successor, Nicomedes I, founded

, which soon rose to great prosperity, and during his long reign ( BC), as well as those of his successors, Prusias I, Prusias II and Nicomedes II (149–91 BC), the kings of Bithynia had a considerable standing and influence among the minor monarchies of

. But the last king, Nicomedes IV, was unable to maintain himself in power against Mithridates VI of Pontus. After being restored to his throne by the

Roman Senate The Roman Senate () was the highest and constituting assembly of ancient Rome and its aristocracy. With different powers throughout its existence it lasted from the first days of the city of Rome (traditionally founded in 753 BC) as the Sena ...

, he bequeathed his kingdom through his will to the

(74 BC). The coinage of these kings show their regal portraits, which tend to be engraved in an extremely accomplished

style.

Roman province

As a

, the boundaries of Bithynia changed frequently. During this period, Bithynia was commonly united for administrative purposes with the province of Pontus within the

Roman Empire The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...

. This was the situation at the time of

Emperor The word ''emperor'' (from , via ) can mean the male ruler of an empire. ''Empress'', the female equivalent, may indicate an emperor's wife (empress consort), mother/grandmother (empress dowager/grand empress dowager), or a woman who rules ...

Trajan Trajan ( ; born Marcus Ulpius Traianus, 18 September 53) was a Roman emperor from AD 98 to 117, remembered as the second of the Five Good Emperors of the Nerva–Antonine dynasty. He was a philanthropic ruler and a successful soldier ...

, when

Pliny the Younger Gaius Plinius Caecilius Secundus (born Gaius Caecilius or Gaius Caecilius Cilo; 61 – ), better known in English as Pliny the Younger ( ), was a lawyer, author, and magistrate of Ancient Rome. Pliny's uncle, Pliny the Elder, helped raise and e ...

was appointed governor of the combined provinces (109/110111/112), a circumstance which has provided historians with valuable information concerning the Roman provincial administration at that time.

Byzantine province

Under the

Byzantine Empire The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...

, Bithynia was again divided into two provinces, separated by the Sangarius. Only the area to the west of the river retained the name of Bithynia. Bithynia attracted much attention because of its roads and its strategic position between the frontiers of the

Danube The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...

in the north and the

Euphrates The Euphrates ( ; see #Etymology, below) is the longest and one of the most historically important rivers of West Asia. Tigris–Euphrates river system, Together with the Tigris, it is one of the two defining rivers of Mesopotamia (). Originati ...

in the south-east. To secure communications with the eastern provinces, the monumental bridge across the river Sangarius was constructed around 562. Troops frequently wintered at Nicomedia. During this time, the most important cities in Bithynia were

, founded by Nicomedes, and

. The two had a long rivalry with each other over which city held the rank of capital.

Notable people

* Hipparchus of Nicaea (2nd century BC), Greek astronomer, discovered precession and discovered how to predict the timing of eclipses * Theodosius of Bithynia (2nd century BC), Greek astronomer and mathematician * Asclepiades of Bithynia (c. 169 BC – c. 100 BC), Greek physician *

Antinous Antinous, also called Antinoös, (; ; – ) was a Greek youth from Bithynia, a favourite and lover of the Roman emperor Hadrian. Following his premature death before his 20th birthday, Antinous was deified on Hadrian's orders, being worshippe ...

(2nd century), Catamite and eromenos of the Roman Emperor

Hadrian Hadrian ( ; ; 24 January 76 – 10 July 138) was Roman emperor from 117 to 138. Hadrian was born in Italica, close to modern Seville in Spain, an Italic peoples, Italic settlement in Hispania Baetica; his branch of the Aelia gens, Aelia '' ...

Cassius Dio Lucius Cassius Dio (), also known as Dio Cassius ( ), was a Roman historian and senator of maternal Greek origin. He published 80 volumes of the history of ancient Rome, beginning with the arrival of Aeneas in Italy. The volumes documented the ...

(c. 155 – c. 235), Roman historian,

senator A senate is a deliberative assembly, often the upper house or Legislative chamber, chamber of a bicameral legislature. The name comes from the Ancient Rome, ancient Roman Senate (Latin: ''Senatus''), so-called as an assembly of the senior ...

, and

consul Consul (abbrev. ''cos.''; Latin plural ''consules'') was the title of one of the two chief magistrates of the Roman Republic, and subsequently also an important title under the Roman Empire. The title was used in other European city-states thro ...

* Arrian (Lucius Flavius Arrianus), Greek historian, c. 86–160 * Helena, mother of

Constantine the Great Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...

* Phrynichus Arabius (2nd century), grammarian * Auxentius of Bithynia (c. 400 – 473), hermit * Hypatius of Bithynia (died c. 450), hermit * Vendemianus of Bithynia (6th century), hermit