The World Heritage Committee of the UN's cultural agency Unesco has requested that Turkey submit a report on the state of the conservation of the Hagia Sophia.
Unesco has expressed “grave concerns” over the consequences of Turkey’s plans to convert the historic site into a mosque, and has demanded that "an updated report on the state of conservation of the property” be filed by February 1, 2022. It also said it "deeply regrets the lack of dialogue and information" over Turkey's intention to change the status of the Hagia Sophia museum and urged Turkey to engage in international cooperation and dialogue before any further major changes are implemented.
In 2020, Turkey announced that it would be converting the Byzantine-era Hagia Sophia cathedral from a museum into a mosque, sparking fury from the international community. The structure was first built as a church between 532 and 537 AD under emperor Justinian I and is considered the most important Byzantine relic. After the Ottoman conquest in 1453 of Constantinople, now Istanbul, it was turned into a mosque before being converted into a museum in 1935, after the establishment of the modern, secular Turkish republic in 1923.
Hagia Sophia was added to the list of Unesco's World Heritage Sites in 1985. It was Turkey's most popular tourist attraction in 2019 with 3.8 million visitors. In July 2020, congregational prayers were held inside Hagia Sophia for the first time in 86 years.
The World Heritage Committee is currently meeting in China for its annual session to review its list of sites with UNESCO's coveted World Heritage label, which boosts the sites' prestige and tourism.
If it is unhappy with the state of conservation of a site, it can be listed as in danger or even deleted, as happened this year with the English city of Liverpool's waterfront.