Constantinople

Constantinople was the capital of the East Roman/Byzantine Empire for more than 1,000 years and is one of the most important cities in world and religious history. Now known as Istanbul, it is located on the Bosphorus Strait in Anatolia on the site of the ancient city of Byzantium. The city was founded by the Roman Emperor Constantine I as “New Rome” in 330 CE to move his imperial capital closer to the frontiers of the empire. For much of its history, Constantinople was the largest and most affluent city in Europe, and its location allowed it to control major trade routes to Asia. It also provided western Europe with a significant defense from both barbarian and Islamic invasions for several centuries. A prime example of the city's opulence is the jewel of Byzantine architecture, the Hagia Sophia, which was the largest church structure in the world for more than a 1,000 years. Constantinople's capture in 1453 by the Ottoman Empire is considered by many historians to mark the end of the Middle Ages, as refugees from the city contributed to the Renaissance by bringing an influx of Greco-Roman culture to the rest of Europe.

Constantinople's role in the history of Christianity cannot be overstated. Its bishop, the Patriarch of Constantinople, was recognized as second in honor only to the pope of Rome in 381, and the tradition that the apostle Andrew had evangelized Byzantium allowed the city to bolster its claim to such prestige. Because the Byzantine emperors desired to ensure that imperial unity was not threatened by Christian division, they summoned seven ecumenical councils during the first millennium to solve major theological disputes; four of these councils were held either in Constantinople or its suburb Chalcedon. In 1054, tensions between the bishops of Rome and Constantinople led to the “Great Schism” between what are known today as the Roman Catholic and Eastern Orthodox churches, which remain the two largest Christian communions. Due to the schism, the patriarchate of Constantinople became the preeminent see in the Eastern Orthodox Church, a position that it still holds.

After Sultan Mehmed II captured the city, he made it the capital of the Ottoman Empire, thus transforming the city from a Christian stronghold into one of the most important Islamic cities in the world. Constantinople's fall was a major blow to Christendom and its popular belief that the city was protected by God and therefore unconquerable. Conversely, many Muslims interpreted their victory as divine affirmation of Islam's superiority over Christianity. It remains one of the world's largest predominantly Muslim cities; however, in the 20th century, the secularization of the city together with the rise of anti-Turkish Arab nationalism, considerably weakened its reputation in the Islamic world. The Republic of Turkey officially renamed the city Istanbul in 1930.