Short answers, pulled from the story.
On the 11th of May 330, Constantine the Great officially proclaimed the ancient city of Byzantium as the new capital and renamed it Constantinople. This event marked the beginning of an era where the location served as the heart of three great empires over the next sixteen centuries.
Megarian colonists founded the Greek colony of Byzantium around 657 BCE, claiming descent from the mythical Byzas, son of the god Poseidon. The city's early history was marked by its strategic location, which allowed it to thrive as a trading hub while also making it a target for powerful empires.
Sultan Mehmed II captured Constantinople on the 29th of May 1453 after a 55-day siege, killing the last Roman emperor, Constantine XI. This event transformed the city into an Islamic stronghold and marked the final chapter of Constantinople as a Christian capital.
On the 29th of October 1923, the Grand National Assembly of Turkey declared the establishment of the Turkish Republic with Ankara as its capital. Mustafa Kemal Atatürk became the Republic's first President, and the city now known as Istanbul was overlooked for the new capital during the interwar period.
The city's population has swelled to over 15 million people, with nearly two-thirds living on the European side and the remainder on the Asian side. This unique demographic split has shaped the city's culture and politics, creating a distinct division across the Bosphorus Strait.
Istanbul Pride became the first gay pride event in a Muslim-majority country when it was held for the first time in 2003. Since 2015, all types of parades at Taksim Square and İstiklal Avenue have been denied permission by the AKP government, citing security concerns, but hundreds of people have defied the ban each year.