(Local and foreign visitors, with the Byzantine-era monument of Hagia Sophia in the background, stroll at Sultanahmet square in Istanbul August 23, 2013. The number of foreign visitors arriving in Turkey grew at its slowest pace for eight months in July, as the impact of anti-government protests and the Muslim fasting month of Ramadan took their toll, data showed on Friday. Foreign arrivals rose 0.48 percent year-on-year last month to 4.59 million people, according to the Tourism Ministry figures, the lowest rise since November. The number of visitors rose 4.93 percent the previous month. REUTERS/Murad Sezer )

(Hagia Sophia in Istanbul August 23, 2013. REUTERS/Murad Sezer )

It has served as the exalted seat of two faiths since its vast dome and lustrous gold mosaics first levitated above Istanbul in the 6th Century: Christendom’s greatest cathedral for 900 years and one of Islam’s greatest mosques for another 500.

Today, the Hagia Sophia, or Ayasofya in Turkish, is officially a museum: Turkey’s most-visited monument, whose formally neutral status symbolizes the secular nature of the modern Turkish state.

But tens of thousands of Muslim worshippers gathering there on Saturday hope it will again be a mosque, a dream they believe Prime Minister Tayyip Erdogan can fulfill.

There are even rumors – denied by the government – that Erdogan, a religious conservative who is seeking the presidency at an election in August, could lead prayers there one day soon.

“This is a serious push to break Ayasofya’s chains,” said Salih Turan, head of the Anatolia Youth Association, which has collected 15 million signatures to petition for it to be turned back into a mosque.