Hagia Sophia (literally 'the Holy Wisdom'; Turkish: Ayasofya; Koinē Greek: Ἁγία Σοφία, romanized: Hagía Sophía; Latin: Sancta Sophia), officially the Hagia Sophia Grand Mosque (Turkish: Ayasofya-i Kebir Cami-i Şerifi) and formerly the Church of the Holy Wisdom (Greek: Ναός της Αγίας του Θεού Σοφίας, romanized: Naós tis Ayías tou Theoú Sofías), is a Late Antique place of worship in Istanbul, designed by the Greek geometers Isidore of Miletus and Anthemius of Tralles.
- It was known as Sankta Sophia or Santa Sophia. It was the most massive church of the Eastern Roman Empire and the emperors desired that it should, by its high quality of art, be unique and suited to the empire… For nine hundred years, it witnessed Greek services and smelt all the incense used in Greek worship. Then for four hundred and eighty years, it heard the azan in Arabic and lines of devotees for namaz stood on its floor stones… Ask those walls to relate to you their story, and narrate their experiences to you. Maybe the study of yesterday and today will enable you to remove the curtain and peep into the future. But those stones and walls are silent. They had seen a lot of Jumma namaz and Sunday services. A daily exhibition is now their lot. The world keeps changing, but they stay. On their worn-out faces is an apparent smirk and a mellow voice as if whispering: how ignorant and foolish is this human creature who does not learn by his thousands of years of experience and repeats the same follies.
- The rapidity with which Mustapha Kemal Ataturk rid himself of his parsons makes one of the most remarkable chapters in history. He hanged thirty-nine of them out of hand, the rest he flung out, and St. Sophia in Constantinople is now a museum!
- Adolf Hitler (1 August 1942), quoted in Gerhard L. Weinberg (ed.), Hitler's Table Talk, 1941–1944 (2008), p. 458
- ...I thought the times were over when after conquering the others, Christian colonial powers would convert mosques into churches, and Muslim powers would turn churches into mosques. This is falling back into a mindset of Crusade times and in the case of the most prestigious church of Eastern Christianity, it harms Christian-Muslim relations around the globe...
- Dr. Thomas Schirrmacher (WEA Secretary General Bishop) Nov 2021 
Encyclopedic article on Hagia Sophia on Wikipedia