The city that served as the capital of the Ottoman Empire was Istanbul, originally known as Byzantium and later Constantinople. After the Ottoman conquest in 1453, Sultan Mehmed II made it the capital and transformed it into a vibrant center of culture, trade, and governance. The city's strategic location between Europe and Asia facilitated commerce and cultural exchanges, contributing to the empire's prosperity. Istanbul remained the capital until the dissolution of the Ottoman Empire in the early 20th century, leaving a lasting legacy in history and architecture.