The city that served as the capital of the Byzantine Empire is Constantinople. Founded by the Roman Emperor Constantine the Great in 330 AD, it was strategically located between Europe and Asia on the Bosporus Strait. This position made Constantinople a major center for trade, culture, and politics. The city is renowned for its architectural masterpieces, including the Hagia Sophia and the Hippodrome, and played a pivotal role in the Christianization of the region. As the capital of the Byzantine Empire, it remained significant until its conquest by the Ottoman Empire in 1453, marking the end of the Byzantine era.