Which empire used Constantinople as its capital until the city fell in 1453?

The Byzantine Empire used Constantinople as its capital until the city fell in 1453.

The Byzantine Empire was the eastern continuation of the Roman Empire. Its inhabitants generally called themselves Romans, while modern historians use “Byzantine” to distinguish their Greek-speaking, Christian state from earlier and western Roman rule. Constantinople, founded as an imperial capital by Constantine the Great in 330, occupied a strategic position between Europe and Asia.

The city controlled important sea routes linking the Black Sea and the Mediterranean. Its massive Theodosian Walls, built and strengthened in the fifth century, helped it withstand repeated attacks for centuries. Constantinople was also a center of Orthodox Christianity, imperial administration, scholarship, and long-distance commerce.

The Ottoman sultan Mehmed II captured the city on 29 May 1453 after a siege. The conquest ended the Byzantine Empire and made Constantinople the Ottoman capital. The city was officially renamed Istanbul in the twentieth century, although “Constantinople” continued to be used historically and internationally for much of the intervening period.