Simply put, Hagia Sophia in Istanbul is one of the most magnificent, influential, historic, and revered buildings on Earth. For centuries, it served as the greatest church in Christendom. It was home to the Byzantine Emperor and Orthodox Patriarch (the “eastern pope”), and a beacon of civilization during Western Europe’s so-called “dark ages.” When Muslims conquered Constantinople, this great church suddenly became one of the world’s greatest mosques. And when it was secularized in the 20th cent