Final answer:
Istanbul has traditionally been considered the seat of Eastern Christianity.
Step-by-step explanation:
Istanbul has traditionally been considered the seat of Eastern Christianity. It became the capital of the Byzantine Empire in the 4th century and it remained an important center of Christianity even after the Ottoman Empire conquered it in 1453. Many significant Orthodox Christian churches and institutions are located in Istanbul, such as the Hagia Sophia and the Ecumenical Patriarchate.
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