Turkish President Recep Tayyip Erdogan attends the first prayer in Constantinople’s Hagia Sophia on Friday, July 24, after the decision of Turkey’s Council of State to turn the world heritage site back into a mosque.

500 people are allowed inside the mosque for the first prayer, with thousands more expected to join from outside the building.

On July 10, Turkey’s Council of State ruled the landmark to be turned back into a place of worship, overturning a 1934 decree which made the mosque into a museum.

UNESCO, who opposed the move, released a statement following the decision, expressing concerns about the impact it may have on the universal value of the site and called on Turkish authorities "to engage in dialogue" on the matter.