What is the significance of constantinople then and now?

Hello there!

Before

Constantinople was the capital city of the Roman/Byzantine Empire. It was reinaugurated in 324 from ancient Byzantium as the new capital of the Roman  Empire by the Emperor "Constantine the Great" -who ruled the Empire between 306 and 377 AD- and it was considered to be the largest and wealthiest city in Europe. The city was largely known for its architectural masterpieces such as the Greek Orthodox cathedral, the sacred Imperial palace and the Galata Tower. Constaninople was famed for its massive and complex defences. It was first settled in the 7th century BC, it developed into a thriving port due to its geographical location between Europe and Asia and its natural harbor. The fallen of this city had different reasons related to its wealthiest situations and issues with the government of the Emperor.

Now

Constantinople was located in which nowadays is Turkey, that is now known as Istanbul.  Istanbul is the place where this ancient city was built and considered to be the capital for Rome. The Republic of Turkey declared this city's new name officialy in 1923. This was because the city had been called by several names over the centuries. Nowadays, this city is pretty well-known for its trading treats.

im so sorry i dont know