Is Hagia Sophia a Mosque? The Full Story

Yes, Hagia Sophia is a mosque, and it has been an active one again since 24 July 2020, when it reopened for Muslim worship as the Hagia Sophia Grand Mosque (Ayasofya-i Kebir Cami-i Şerifi). Five daily prayers are held on its ground floor, and curtains now conceal the great apse mosaic at prayer times. But if you’re asking “is Hagia Sophia a mosque,” you’re really asking about one of the strangest career paths any building has ever had: cathedral for 916 years, mosque for 481, museum for 85, and mosque once more. Here’s the full story, era by era, and what it means for your visit today.

Hagia Sophia before Islam: 916 years as a church

Long before it was the Hagia Sophia mosque, this was the largest cathedral on Earth. Emperor Justinian I inaugurated it on 27 December 537, and it served as the cathedral of Constantinople until 1453, the ceremonial heart of Eastern Christianity. Byzantine emperors were crowned here on the omphalion, the circle of coloured marble discs still set into the floor today.

The Hagia Sophia church story has one dramatic interruption. After the Fourth Crusade sacked Constantinople in 1204, the building spent 57 years as a Latin Catholic cathedral before returning to Orthodox hands in 1261. Enrico Dandolo, the Venetian doge who led the crusade, was buried in the upper gallery, and his grave marker survives there. The whole Byzantine arc, from Justinian’s engineers to the last imperial coronation, is told in full on our history page.

What happened when it became a mosque in 1453?

On 29 May 1453, Mehmed II, remembered as the Conqueror, took Constantinople, and the great church was converted into a mosque the same week. The first Friday prayer was held on 1 June 1453, just three days after the city fell.

Conversion did not mean destruction. The Ottomans added what a mosque needs, a mihrab and a minbar, and over the centuries four minarets rose around the building, one brick and three stone. The Christian mosaics were gradually covered rather than torn out, which is a large part of why so many golden mosaics survive for visitors to see now.

The mosque centuries: 1453 to 1935

For 481 years Hagia Sophia served as an imperial mosque, and the sultans never stopped investing in it. The great architect Mimar Sinan added structural buttresses and two of the minarets in the 16th century. Mahmud I added an elegant library in the 18th. In the 1840s, the calligrapher Kazasker Mustafa İzzet Efendi produced the eight giant roundels, each about 7.5 metres across, naming Allah, the Prophet Muhammad, the four caliphs, and the Prophet’s grandsons Hasan and Husayn. They still dominate the nave today.

In 1847–1849 the Swiss-Italian Fossati brothers restored the entire building for the sultan. Crucially, they documented many of the hidden Byzantine mosaics before re-covering them, leaving a record that later restorers would rely on.

Why did Atatürk turn it into a museum?

In 1934, the young Turkish Republic under Atatürk issued a decree secularizing the building, and Hagia Sophia opened as a museum on 1 February 1935. For 85 years it belonged to no single faith. Restorers uncovered mosaics that had been hidden for centuries, and the building became a shared symbol: part church, part mosque, wholly a monument. In 1985 it was inscribed as part of the Historic Areas of Istanbul UNESCO World Heritage Site.

How did Hagia Sophia become a mosque again in 2020?

On 10 July 2020, Turkey’s Council of State annulled the 1934 decree that had created the museum, ruling that the building’s original endowment designated it a mosque. Two weeks later, on 24 July 2020, Hagia Sophia reopened for Muslim worship and officially became the Hagia Sophia Grand Mosque, its first prayers since the museum era began.

Inside, the changes were significant but reversible. Carpets now cover the ground floor for prayer, though the omphalion, where emperors were once crowned, was deliberately left uncovered within the carpet. At each prayer time, curtains are drawn across the apse mosaic of the Virgin and Child, then opened again afterwards. The mosaics themselves were not touched.

So is Hagia Sophia a mosque or a museum today?

It is a working mosque that also welcomes tourists from all over the world, and since 15 January 2024 the two roles have separate spaces. Worshippers pray on the ground floor, free of charge, as at any mosque. Foreign visitors buy a ticket for a dedicated route through the upper gallery, entering by a separate visitor entrance on the southwest side, which is where the best mosaics are anyway. Expect tourist entry to pause for roughly 30 to 60 minutes around each of the five daily prayers, with the longest pause around Friday midday.

None of this makes the building hard to visit; it just rewards a little planning. Our plan your visit guide covers entrances, timing and what to combine it with, and you can book skip-the-line entry ahead so the only queue you think about is the one for the tram home.

Sixteen centuries in, Hagia Sophia is still doing what it has always done: serving as a house of worship while the world files through to stare at its dome. Cathedral, mosque, museum, mosque again. Few buildings have answered the same question four different ways, and fewer still have made every answer this interesting.