I have visited the Hagia Sophia thrice and each time marveled at its magnificence. The church built by the emperor Justinian was completed in 537 AD and for almost one thousand years (until the Basilica of Rome was completed in 1506) Hagia Sophia was the greatest church in the Christendom.
I have great respect for the great warrior of Islam Mehmet the Conqueror. What he did was in line with the custom of the time. He was however a mortal man and hence likely to occasional err as well. Purchased or not (who can deny a victorious sovereign?), converting a Church into a Mosque, in my opinion, was wrong. By the way, I think that had Bayezid Yildrim not been eliminated by Amir Taimur, he would probably have captured Constantinople 50 years earlier.
I am also a fan of Ata-Turk, he should have handed it back to the Christian population of Turkey; however, what he did was the next best thing. I, therefore, do not agree with its re-conversion to the mosque. On this basis, the Indian Courts' decision to convert Babri Masjid back to the Ram Temple at Ayodhya is also justified.
How can this be called a victory for the Muslims? The Islam I believe in teaches Muslims to respect other religions and their places of worship:
Say, "We have believed in Allah and in what was revealed to us and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Descendants, and in what was given to Moses and Jesus and to the prophets from their Lord. We make no distinction between any of them, and we are Muslims [submitting] to Him.”
(The Holy Quran 3:84)
Church, Museum, or a Mosque, Hagia Sophia remains one of the greatest buildings in the world. In addition to this Istanbul; a city I love for its great location, historical sights, and truly great food; boasts at least three other truly awe-inspiring monuments, namely the Topkapi Palace, Sultan Ahmed Mosque and the underground water storage (Basilica Cistern). I would, therefore, urge all those who can manage to visit Istanbul at least once in their lifetime.