Nicomedia (/ˌnɪkəˈmiːdiə/;[1] Greek: Νικομήδεια, Nikomedeia; modern İzmit) was an ancient Greek city in what is now Turkey. In 286 Nicomedia became the eastern and most senior capital city of the Roman Empire (chosen by Diocletian who assumed the title Augustus of the East), a status which the city maintained during the Tetrarchy system (293–324).

The Tetrarchy ended with the Battle of Chrysopolis (Üsküdar) in 324, when Constantine defeated Licinius and became the sole emperor. In 330 Constantine chose for himself the nearby Byzantium (which was renamed Constantinople, modern Istanbul) as the new capital of the Roman Empire.

Nicomedia is located in Turkey
Shown within Turkey
Nicomedia is located in Sea of Marmara
Nicomedia (Sea of Marmara)
RegionKocaeli Province
Coordinates40°46′N 29°56′E / 40.767°N 29.933°ECoordinates: 40°46′N 29°56′E / 40.767°N 29.933°E


It was founded in 712/11 BC as a Megarian colony and was originally known as Astacus (/ˈæstəkəs/; Ancient Greek: Ἀστακός, "lobster").[2] After being destroyed by Lysimachus,[3] it was rebuilt by Nicomedes I of Bithynia in 264 BC under the name of Nicomedia, and has ever since been one of the most important cities in northwestern Asia Minor. The great military commander Hannibal Barca came to Nicomedia in his final years and committed suicide in nearby Libyssa (Diliskelesi, Gebze). The historian Arrian was born there.

Byzantine - Belt Section with Medallions of Constantius II and Faustina - Walters 57527
This section of a belt depicting medallions honoring Constantius II and Faustina was minted in Nicomedia.[4] The Walters Art Museum.

Nicomedia was the metropolis and capital of the Roman province of Bithynia under the Roman Empire. It is referenced repeatedly in Pliny the Younger's Epistles to Trajan during his tenure as governor of Bithynia.[5] Pliny, in his letters, mentions several public buildings of the city such as a senate-house, an aqueduct, a forum, a temple of Cybele, and others, and speaks of a great fire, during which the place suffered much.[6] Diocletian made it the eastern capital city of the Roman Empire in 286 when he introduced the Tetrarchy system.

Persecutions of 303

Nicomedia was at the center of the Diocletianic Persecution of Christians which occurred under Diocletian and his Caesar Galerius. On 23 February 303 AD, the pagan festival of the Terminalia, Diocletian ordered that the newly-built church at Nicomedia be razed, its scriptures burnt, and its precious stones seized.[7] The next day he issued his "First Edict Against the Christians," which ordered similar measures to be taken at churches across the Empire.

The destruction of the Nicomedia church incited panic in the city, and at the end of the month a fire destroyed part of Diocletian's palace, followed 16 days later by another fire.[8] Although an investigation was made into the cause of the fires, no party was officially charged, but Galerius placed the blame on the Christians. He oversaw the execution of two palace eunuchs, who he claimed conspired with the Christians to start the fire, followed by six more executions through the end of April 303. Soon after Galerius declared Nicomedia to be unsafe and ostentatiously departed the city for Rome, followed soon after by Diocletian.[8]

Later Empire

Tetrarchy map3
Map of the Roman Empire during the Tetrarchy system, showing the dioceses and the four tetrarchs' zones of influence. Nicomedia was the eastern and most senior capital city, chosen by Diocletian who assumed the title Augustus of the East.

Nicomedia remained as the eastern (and most senior) capital of the Roman Empire until co-emperor Licinius was defeated by Constantine the Great at the Battle of Chrysopolis (Üsküdar) in 324. Constantine mainly resided in Nicomedia as his interim capital city for the next six years, until in 330 he declared the nearby Byzantium (which was renamed Constantinople) the new capital. Constantine died in a royal villa in the vicinity of Nicomedia in 337. Owing to its position at the convergence of the Asiatic roads leading to the new capital, Nicomedia retained its importance even after the foundation of Constantinople.[9]

A major earthquake, however, on 24 August 358, caused extensive devastation to Nicomedia, and was followed by a fire which completed the catastrophe. Nicomedia was rebuilt, but on a smaller scale.[10] In the sixth century under Emperor Justinian I the city was extended with new public buildings. Situated on the roads leading to the capital, the city remained a major military center, playing an important role in the Byzantine campaigns against the Caliphate.[11] From inscriptions we learn that in the later period of the empire Nicomedeia enjoyed the honour of a Roman colony.[12]

In 451, the local bishopric was promoted to a Metropolitan see under the jurisdiction of the Ecumenical Patriarchate of Constantinople.[13] The metropolis of Nicomedia was ranked 7th in the Notitiae Episcopatuum among the metropolises of the patriarchate.[14] In the eighth century the Emperor Constantine V established his court there for a time, when plague broke out in Constantinople and drove him from his capital in 746–47.[15] From the 840s on, Nicomedia was the capital of the thema of the Optimatoi. By that time, most of the old, seawards city had been abandoned and is described by the Persian geographer Ibn Khurdadhbih as lying in ruins, with settlement restricted to the hilltop citadel.[11] In the 1080s, the city served as the main military base for Alexios I Komnenos in his campaigns against the Seljuk Turks, and the First and Second Crusades both encamped there.

The city was briefly held by the Latin Empire following the fall of Constantinople to the Fourth Crusade in 1204: in late 1206 the seneschal Thierry de Loos made it his base, converting the church of Saint Sophia into a fortress; however, the Crusader stronghold was subjected to constant raids by the Emperor of Nicaea Theodore I Laskaris, during which de Loos was captured by Nicaean soldiers; by the summer of 1207 Emperor Henry of Flanders agreed to evacuate Nicomedia in exchange for de Loos and other prisoners Emperor Theodore held.[16] The city remained in Byzantine control for over a century after that, but following the Byzantine defeat at the Battle of Bapheus in 1302, it was threatened by the rising Ottoman beylik. The city was twice sieged and blockaded by the Ottomans (in 1304 and 1330) before finally succumbing in 1337.[11]


During the Empire, Nicomedia was a cosmopolitan and commercially prosperous city which received all the amenities appropriate for a major Roman city. Nicomedia was well known for having a bountiful water supply from two to three aqueducts,[17] one of which was built in Hellenistic times. Pliny the Younger complains in his epistulae to Trajan, written in 110 AD, that the Nicomedians wasted 3,518,000 sesterces on an unfinished aqueduct which twice ran into engineering troubles. Trajan instructs him to take steps to complete the aqueduct, and to investigate possible official corruption behind the large waste of money.[18] Under Trajan, there was also a large Roman garrison.[19] Other public amenities included a theatre, a colonnaded street typical of Hellenistic cities and a forum.[20]

The major religious shrine was a temple of Demeter, which stood in a sacred precinct on a hill above the harbor.[5] The city adopted official cults of Rome avidly, there were temples dedicated to the Emperor Commodus,[21] a sacred precinct of the city dedicated to Octavian,[22] and a temple of Roma dedicated during the late-Republic.[5]

The city was sacked in AD 253 by the Goths, but when Diocletian made the city his capital in 283 AD he undertook grand restorations and built an enormous palace, an armory, mint and new shipyards.[5]

Notable natives and residents

S. Pantaleon from Nicomedian catacomb (10-11 c., GIM) by shakko

St. Pantaleon



Istanbul - Museo archeol. - Diocleziano (284-305 d.C.) - Foto G. Dall'Orto 28-5-2006


Licinius gold multiple CdM Beistegui 232 (cropped)



Nicomedia Aqueduct, Izmit, Turkey (39171950052)
Ruins of a Nicomedian aqueduct in İzmit

The ruins of Nicomedia are buried beneath the densely populated modern city of İzmit, which has largely obstructed comprehensive excavation. Before the urbanization of the 20th century occurred, select ruins of the Roman-era city could be seen, most prominently sections of the Roman defensive walls which surrounded the city and multiple aqueducts which once supplied Nicomedia's water. Other monuments include the foundations of a 2nd-century AD marble nymphaeum on İstanbul street, a large cistern in the city's Jewish cemetery, and parts of the harbor wall.[5]

The 1999 İzmit earthquake, which seriously damaged most of the city, also led to major discoveries of ancient Nicomedia during the subsequent debris clearing. A wealth of ancient statuary was uncovered, including statues of Hercules, Athena, Diocletian and Constantine.[23]

In the years after the earthquake, the Izmit Provincial Cultural Directorate appropriated small areas for excavation, including the site identified as Diocletian's Palace and a nearby Roman theatre. In April 2016 a more extensive excavation of the palace was begun under the supervision of the Kocaeli Museum, which estimated that the site covers 60,000 square meters (196,850 square feet).[24]

See also


  1. ^ ""Nicomedia" in the American Heritage Dictionary". Archived from the original on 2014-09-30. Retrieved 2012-07-03.
  2. ^ Peter Levi (ed.). Guide to Greece By Pausanias. p. 232. ISBN 0-14-044225-1.
  3. ^ Cohen, Getzel M. The Hellenistic settlements in Europe, the islands, and Asia Minor. p. 400. ISBN 0-520-08329-6.
  4. ^ "Belt Section with Medallions of Constantius II and Faustina". The Walters Art Museum.
  5. ^ a b c d e W.L. MacDonald (1976). "NICOMEDIA NW Turkey". The Princeton Encyclopedia of Classical Sites. Princeton University Press.
  6. ^ Pliny the Younger, Epist. 10.42, 46.
  7. ^ Timothy D. Barnes (1981). Constantine & Eusebius. p. 22.
  8. ^ a b Patricia Southern (2001). The Roman Empire: From Severus to Constantine. p. 168.
  9. ^ See C. Texier, Asie mineure (Paris, 1839); V. Cuenet, Turquie d'Asie (Paris, 1894).
  10. ^ See Ammianus Marcellinus 17.7.1–8
  11. ^ a b c Kazhdan, Alexander, ed. (1991), Oxford Dictionary of Byzantium, Oxford University Press, pp. 1483–1484, ISBN 978-0-19-504652-6
  12. ^  Smith, William, ed. (1854–1857). "Nicomedeia". Dictionary of Greek and Roman Geography. London: John Murray.
  13. ^ Kiminas, Demetrius (2009). The Ecumenical Patriarchate. Wildside Press LLC. p. 79. ISBN 978-1-4344-5876-6.
  14. ^ Terezakis, Yorgos. "Diocese of Nicomedia (Ottoman Period)". Εγκυκλοπαίδεια Μείζονος Ελληνισμού, Μ. Ασία. Retrieved 13 November 2012.
  15. ^ David Turner, The Politics of Despair: The Plague of 746–747 and Iconoclasm in the Byzantine Empire, The Annual of the British School at Athens, Vol. 85 (1990), p428
  16. ^ Geoffrey de Villehardouin, translated by M. R. B. Shaw, Joinville and Villehardouin: Chronicles of the Crusades (London: Penguin, 1963), pp. 147, 154–56
  17. ^ Libanius. Oratories. p. 61.7.18.
  18. ^ Pliny the Younger. Epistulae. p. 10.37 & .38.
  19. ^ Pliny the Younger. Epistles. p. 10.74.
  20. ^ Pliny the Younger. Epistles. p. 10.49.
  21. ^ Dio Cassius. Roman History. p. 73.12.2.
  22. ^ Cassius Dio. Roman History. p. 51.20.7.
  23. ^ "Ancient underground city in izmit excites archaeology world". Hürriyet Daily News. 2016-03-04. Retrieved 2018-01-14.
  24. ^ "Ancient underground city in izmit excites archaeology world". Hürriyet Daily News. 2016-03-04. Retrieved 2018-01-14.

 This article incorporates text from a publication now in the public domainSmith, William, ed. (1854–1857). "Nicomedeia". Dictionary of Greek and Roman Geography. London: John Murray.

Adrian and Natalia of Nicomedia

Saint Adrian (also known as Hadrian) or Adrian of Nicomedia (died 4 March 306) was a Herculian Guard of the Roman Emperor Galerius Maximian. After becoming a convert to Christianity with his wife Natalia, Adrian was martyred at Nicomedia.


Arbeila was a town of ancient Bithynia on the coast of the Sinus Astacenus west of Nicomedia. Its name does not appear in ancient authors but is inferred from epigraphic and other evidence.Its site is located near Tuzla, in Asiatic Turkey.


Arrian of Nicomedia (; Greek: Ἀρριανός Arrianos; Latin: Lucius Flavius Arrianus; c. 86/89 – c. after 146/160 AD) was a Greek historian, public servant, military commander and philosopher of the Roman period.The Anabasis of Alexander by Arrian is considered the best source on the campaigns of Alexander the Great. However, more recently, even though modern scholars have generally preferred Arrian to other extant primary sources, this attitude towards Arrian is beginning to change in the light of studies into Arrian's method.

Astacus (Bithynia)

Astacus (Greek Ἀστακός Βιθυνίας) is the name of an ancient city in Bithynia; it was also called Olbia . Stephanus of Byzantium records an aetiological myth that it was founded by Astacus, son of Poseidon and the nymph Olbia. The city was founded in the Second Greek colonisation by the Megarans together with the Athenians.The traditional date of the founding is 712/11 BC, the first year of the 17th Olympiad.

However, "Diodorus Siculus" (aka "Library of History"), Book XII, Chapter 34, writes that in the year 435 BCE "And while these events were taking place [the battle of the Athenians on the isthmus near Pallenê against the Potidaeans] the Athenians founded in the Propontis a city which was given the name of Astacus." (Perhaps Diodorus was incorrect.)

King Zipoetes I of Bithynia made two attempts to absorb Astacus into his kingdom: in 315 BC he was defeated by succors sent by Antigonus Monophthalmos. In 301 BC, he was successful, but the city was destroyed in the war.

Nicomedes I, son of Zipoetes, founded a new city to replace Astacus across from its former location, which he named Nicomedia after himself, bringing some of the Astacan cults to the new site. Nicomedia remained the capital of Bithynia, and became one of the great cities of the Roman east; the Emperor Diocletian made it his usual capital.

Its site is located near the modern Baş İskele.

Brunca (Bithynia)

Brunca or Brunka or Brunga was a town of ancient Bithynia on the coast of the Propontis, on the road from Nicomedia to Libyssa, 13 M.P. from the former and 12 M.P. of the latter.Its site is tentatively located near Hereke/Yarımca, in Asiatic Turkey.

Charax (Bithynia)

Charax in Bithynia (Ancient Greek: Χάραξ της Βιθυνίας or Χάρακας της Βιθυνίας) was a Roman and Byzantine port town of ancient Bithynia, in what is now Turkey. It was on the north side of the Sinus Astacenus on the road between the erstwhile Eastern Roman and Byzantine capital Nicomedia and Libyssa. Stephanus of Byzantium calls it a place of great trade.Its site is located near Hereke, in Asiatic Turkey.

Cyprian and Justina

Saints Cyprian and Justina are honored in the Catholic Church, Eastern Orthodox Church and Oriental Orthodoxy as Christians of Antioch, who in 304, during the persecution of Diocletian, suffered martyrdom at Nicomedia (modern-day İzmit, Turkey) on September 26. It is, however, certain that no Bishop of Antioch bore the name of Cyprian.

Dekaton (Bithynia)

Dekaton (Ancient Greek: Δέκατον) was a settlement and station of ancient Bithynia on the road east of Nicomedia, 10 Roman miles east of Nicomedia, whence the name.

Its site is located near 10 Roman miles east of Nicomedia in Asiatic Turkey.

Dionysius II of Constantinople

Dionysius II (Greek: Διονύσιος Β΄), (? – July 1556) was Ecumenical Patriarch of Constantinople from 1546 to 1556.


Eribolum or Eribolon (Ancient Greek: Ἐρίβωλον), or Eribolus or Eribolos (Ἐρίβωλος), or Eriboia (Ἐριβοία), was a port town of ancient Bithynia, on the Sinus Astacenus near Nicomedia. It appears in the Tabula Peutingeriana under the name of Eribulo, south of the bay of Astacus, with the numeral XII, and north of Nicaea; the figure of a house in the Tabula indicates a town, perhaps with warm springs. It is Hyribolum in the Jerusalem Itinerary. Cassius Dio speaks of it as a naval station opposite to Nicomedia. After the Battle of Antioch (in 218), the Roman emperor Macrinus fled to Eribolum seeking passage westwards while avoiding the large port of Nicomedia whose governor was in favour of the emperor Heliogabalus.Its site is located near Yeniköy, in Asiatic Turkey.

Eusebius of Nicomedia

Eusebius of Nicomedia (died 341) was the man who baptised Constantine the Great. He was a bishop of Berytus (modern-day Beirut) in Phoenicia. He was later made the Bishop of Nicomedia, where the imperial court resided. He lived finally in Constantinople from 338 up to his death.


Liada was a town of ancient Bithynia, on the road from Nicomedia to Nicaea.Its site is located near Sarıağıl, in Asiatic Turkey.


Libum or Libon was a town of ancient Bithynia, on the road from Nicomedia to Nicaea.Its site is located near Senaiye, in Asiatic Turkey.

Pope Constantine

Pope Constantine (Latin: Constantinus; 664 – 9 April 715) was Bishop of Rome from 25 March 708 to his death in 715. With the exception of Antipope Constantine, he was the only pope to bear such a "quintessentially" Eastern name of an emperor. During this period, the regnal name was also used by emperors and patriarchs.

Selected as one of the last popes of the Byzantine Papacy, the defining moment of Constantine's pontificate was his 710/711 visit to Constantinople where he compromised with Justinian II on the Trullan canons of the Quinisext Council. Constantine was the last pope to visit Constantinople until Pope Paul VI did in 1967.


Prindea was a town of ancient Bithynia on the road east of Nicomedia. Its name does not occur in ancient authors but is inferred from epigraphic and other evidence.Its site is tentatively located near Hamidiye in Asiatic Turkey.

Prochorus (deacon)

Prochorus (Latin form of the Greek: Πρόχορος (Prochoros)) was one of the Seven Deacons chosen to care for the poor of the Christian community in Jerusalem (Acts 6:5). According to later tradition he was also one of the Seventy Disciples sent out by Jesus in Luke 10.

Tradition calls Prochorus the nephew of Stephen the Protomartyr. St Prochorus accompanied the holy Apostle Peter, who ordained him to be the bishop in the city of Nicomedia. He is also thought to have been a companion of John the Apostle, who consecrated him bishop of Nicomedia in Bithynia. He was wrongly thought to have been the author of the apocryphal Acts of John, which is dated by present scholars to the end of the 2nd century. According to the late tradition he was the bishop of Antioch and ended his life as a martyr in Antioch in the 1st century.

In Orthodox iconography he is always depicted as a scribe of John the Evangelist.

Sea of Marmara

The Sea of Marmara (; Turkish: Marmara Denizi), also known as the Sea of Marmora or the Marmara Sea, and in the context of classical antiquity as the Propontis is the inland sea, entirely within the borders of Turkey, that connects the Black Sea to the Aegean Sea, thus separating Turkey's Asian and European parts. The Bosphorus strait connects it to the Black Sea and the Dardanelles strait to the Aegean Sea. The former also separates Istanbul into its Asian and European sides. The Sea of Marmara is a small sea with an area of 11,350 km2 (4,380 sq mi), and dimensions 280 km × 80 km (174 mi × 50 mi). Its greatest depth is 1,370 m (4,490 ft).

Siege of Nicomedia

From 1299, the newly founded Turkic state of the Ottomans had been slowly but surely capturing territory from the Byzantine Greeks. The loss of Nicaea was the beginning of a series of Ottoman expansion that lead to final dissolution of the Byzantine Empire and its scattered Greek successor states.


İzmit, known as Nicomedia in antiquity, is a city in Turkey, the administrative center of the Kocaeli Province as well as the Metropolitan Municipality. It is located at the Gulf of İzmit in the Sea of Marmara, about 100 km (62 mi) east of Istanbul, on the northwestern part of Anatolia. The city center has a population of 300,611 (2011 census). The population of the province (including rural areas) is 1,459,772. Unlike other provinces in Turkey, apart from Istanbul, the whole province is included within the municipality of the metropolitan center.

Nicomedia was the eastern and most senior capital city of the Roman Empire between 286 and 324, during the Tetrarchy introduced by Diocletian. Following Constantine the Great's victory over co-emperor Licinius at the Battle of Chrysopolis in 324, Nicomedia served as an interim capital city for Nova Roma.

Black Sea
Central Anatolia
Eastern Anatolia


This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.