The structure once was one of Christendom’s most significant cathedrals, then a mosque and museum before its reconversion into a Muslim place of worship, reports AP.

President Recep Tayyip Erdogan also attended the prayers inside the sixth-century monument along with around 500 dignitaries.

Thousands of men and women, including many who travelled from across Turkey, quickly filled specially-designated, segregated areas outside of Hagia Sophia, to be part of the first prayers in nearly nine decades.

Many people camped near the structure overnight while dozens of worshipers broke through one police checkpoint to rush toward Hagia Sophia and social distancing practices, in place due to the coronavirus outbreak, were being ignored, Turkish media reported.

Orthodox Church leaders in Greece and the United States, meanwhile, were scheduled to observe ‘a day of mourning’ over the inaugural prayers.

Earlier this month, Erdogan issued a decree restoring the iconic building as a mosque, shortly after a Turkish high court ruled that the Hagia Sophia had been illegally made into a museum more than eight decades ago.

The structure, listed as a UNESCO World Heritage site, has since been renamed “The Grand Hagia Sophia Mosque.”

But the move sparked dismay in Greece, the United States and among Christian churches who had called on Erdogan to maintain it as a museum as a nod to Istanbul’s multi-religious heritage and the structure’s status as a symbol of Christian and Muslim unity.

Pope Francis also expressed his sadness.

Last week Erdogan said: “This is Hagia Sophia breaking away from its captivity chains. It was the greatest dream of our youth.”

“It was the yearning of our people and it has been accomplished,” said Erdogan adding that its conversion into a museum by the republic’s founding leaders as a mistake that is being rectified.

History of Hagia Sophia

Built by the Byzantine Emperor Justinian in 537, Hagia Sophia was turned into a mosque with the 1453 Ottoman conquest of Istanbul.

Mustafa Kemal Ataturk, the founding leader of the secular Turkish republic, converted the structure into a museum in 1934.

Although an annex to the Hagia Sophia, the Sultan’s pavilion, has been open to prayers since the 1990s, religious and nationalists group in Turkey have long yearned for the nearly 1,500-year-old edifice, which they regard as the legacy of Ottoman Sultan Mehmet the Conquerer, to be reverted into a mosque.