8500 A grave that was 8,500 years old was found at the Yenikapı excavations.
685 Colonists from Argos, Korint and Megara settled in Chalcedon [Kadıköy] and established the city there.
668 Byzas, the legendary leader of Megara, is considered to have established Byzantium.
6500 Fikirtepe Culture started to develop on the eastern side of the Bosphorus.
6500 Yenikapı settlement started to be established on the western side of the Bosphorus.
510 Persians seized and raided the city of Byzantium.
478/477 Byzantium was under the hegemony of the Spartan Commander Pausanias for seven months.
478/477 Byzantium became a member of Attika-Delos Maritime Union with the encouragement of Athens.
440/439 Byzantium went from the Attika-Delos Maritime Union to Athens.
412 Although Byzantium and Chalcedon attempted to separate from the Attika-Delos Maritime Union, they did not show much resistance to Athens and continued to be allies with them and pay taxes.
411 Byzantium was under the hegemony of the Spartans as a result of the strengthening of supporters of the oligarchy.
409/408 Byzantium and Chalcedon were forced to ally with Athens again by the Commander Alkibiades from Athens.
405 The Spartan Commander Lysandros ended the administration that supported Athens. He established the oligarchy regime that was loyal to Sparta.
403 The tyranny of the Spartan Commander Klearkhos started in Byzantium.
387 Byzantium became autonomous with the Antalkidas Treaty between the Helens and Persians, and Chalcedon entered under Persian rule.
378 Byzantium became a member of the Second Attika -Delos Maritime Union again.
363 Upon Byzantium’s close relations with Thebai, whose strength grew in the region, Athens captured the city by force of arms and continued the alliance.
355 Byzantium separated from the Attika-Delos Maritime Union with the approval of Athens.
354-353 Byzantium expanded their land through military manoeuvres and political unions/dual citizenship [sympoliteia] contracts with Selymbria [Silivri] and Perinthos [Marmara Ereğlisi].
340/339 The Macedonian King Philip II surrounded Byzantium; however, Byzantium was able to remove the blockade with the help of its old allies.
278 Byzantium was attacked and destroyed by the people of Galat.
266 The Seleucid King Antiochus I and his allies surrounded Byzantium.
251 The Seleucid King Antiochus II embarked on an expedition to Byzantium with his fleet.
202 The Macedonian King Philip II separated Chalcedon from the union founded by Aitos by force, and took them under his rule.
147 Byzantium formed an alliance with Rome with the title of ally city.
146 Byzantium formed an alliance with Rome with the title of ally city.
129 Byzantium fulfilled its liabilities towards Rome during the suppression of the Aristonikos Uprising, which lasted 4 years.
101 Byzantium fulfilled its liabilities towards Rome during the wars against pirates and the Mithridatic Wars.