Constantinople was the capital of the Byzantine Empire, which was the eastern half of the Roman Empire that survived after the fall of the Western Roman Empire in 476 CE. It was a major center of trade and commerce, and was the largest and wealthiest city in Europe for centuries. It was also a major center of culture and learning, and was home to some of the most important religious sites in the world, including the Hagia Sophia and the Church of the Holy Wisdom. Constantinople was also the site of several major battles, including the Fourth Crusade and the Siege of Constantinople in 1453, which marked the end of the Byzantine Empire and the beginning of the Ottoman Empire.
