The capital of the Byzantine Empire was Constantinople, which was originally known as Byzantium before being renamed by Emperor Constantine the Great in 330 AD. The city became a major center for trade, culture, and politics, strategically located at the crossroads of Europe and Asia. It was also the seat of the Eastern Orthodox Church and played a vital role during the Middle Ages. Constantinople's strong defensive walls and wealth helped it withstand numerous sieges until it fell to the Ottoman Empire in 1453, marking the end of the Byzantine Empire.