History of Istanbul

Neolithic artifacts, uncovered by archeologists at the beginning of the 21st century, indicate that Istanbul's historic peninsula was settled as far back as the 6th millennium BCE. That early settlement, important in the spread of the Neolithic Revolution from the Near East to Europe, lasted for almost a millennium before being inundated by rising water levels. The first human settlement on the Asian side, the Fikirtepe mound, is from the Copper Age period, with artifacts dating from 5500 to 3500 BCE. In the European side, near the point of the peninsula (Sarayburnu) there was a settlement during the early 1st millennium BCE. Modern authors have linked it to the possible Thracian toponym Lygos, mentioned by Pliny the Elder as an earlier name for the site of Byzantium.

There is evidence suggesting there were settlements around the region dating as far back as 6700 BC, and it is hard to define if there was any settlement on exact spot at city proper established, but earliest records about city proper begins around 660 BC when Greek settlers from the Attic town of Megara colonized the area and established Byzantium on the European side of the Bosphorus. It fell to the Roman Republic in 196 BC, and was known as Byzantium in Latin until 330, when the city, soon renamed as Constantinople, became the new capital of the Roman Empire. During the reign of Justinian I, the city rose to be the largest in the western world, with a population peaking at close to half a million people. Constantinople functioned as the capital of the Byzantine Empire, which effectively ended with the fall of Constantinople in 1453. Constantinople then became the capital of the Ottoman Turks.

The population had declined during the medieval period, but as the Ottoman Empire approached its historical peak, the city grew to a population of close to 700,000 in the 16th century, once again ranking among the world's most popular cities. With the founding of the Republic of Turkey in 1923, that country's capital moved from Constantinople to Ankara (previously Angora).

Humans have lived in the area now known as Istanbul since at least the Neolithic period. The earliest known settlement dates from 6700 BC, discovered in 2008, during the construction works of the Yenikapı subway station and the Marmaray tunnel at the historic peninsula on the European side. On the Anatolian side, the earliest known settlement is the Fikirtepe mound from the Copper Age period, with artifacts dating from 5500 to 3500 BC. In nearby Kadıköy (Chalcedon) a port settlement dating back to the Phoenicians has been discovered.

The first name of the city was Lygos according to Pliny the Elder in his historical accounts and it was possibly founded by Thracian tribes along with the neighboring settlement of Semystra. Only a few walls and substructures belonging to Lygos have survived to date, near the Seraglio Point, where the Topkapı Palace now stands. Lygos and Semystra were the only settlements on the European side of Istanbul. On the Asian side there was a Phoenician colony.

Byzantion (Βυζάντιον), Latinized as Byzantium, was the next name of the city. The name is believed to be of Thracian origin from the word būzas (“he-goat”). Specifically, it may be derived from the Thracian personal name Byzas. Ancient Greek legend refers to a legendary king Byzas as the leader of the Megarian colonists and eponymous founder of the city. Cape Moda in Chalcedon was the first location which the Greek settlers from Megara chose to colonize in 685 BC, before colonizing Byzantion on the European side of the Bosphorus under the command of King Byzas in 667 BC. Byzantion was established on the site of an ancient port settlement named Lygos During the period of Byzantion, the Acropolis used to stand where the Topkapı Palace stands today.

After siding with Pescennius Niger against the victorious Septimius Severus the city was besieged by Rome and suffered extensive damage in AD 196. Byzantium was rebuilt by the Roman Emperor Septimius Severus and quickly regained its previous prosperity, being temporarily renamed as Augusta Antonina by the emperor, in honor of his son.

The location of Byzantium attracted Constantine the Great in 324 after a prophetic dream was said to have identified the location of the city; this prophecy was probably due to Constantine's final victory over Licinius at the Battle of Chrysopolis (Üsküdar) on the Bosphorus, on 18 September 324, which ended the civil war between the Roman Co-Emperors, and brought an end to the final vestiges of the Tetrarchy system, during which Nicomedia (present-day İzmit, 100 km east of Istanbul) was the most senior capital city of the Roman Empire. Byzantium (now renamed as Nova Roma which eventually became Constantinopolis, i.e. The City of Constantine) was officially proclaimed the new capital of the Roman Empire in 330. At the end of his reign in 337, Constantine declared his three sons as joint heirs of the Roman Empire in a system of co-emperorship. However, the sons could not govern together peacefully and their military rivalry split the empire on the north–south line along the Balkan Peninsula. The territory was officially split in 395 when Theodosius I (ruled, 379–395) died, leaving his son Honorius emperor of the Western Roman Empire, and his other son Arcadius emperor of the Eastern Roman (Byzantine) Empire.