Thousands of worshippers attended the ceremony. With the prayer hall full, many of them prayed in the square itself.

According to reports, Erdogan and several governments in the country since 1950 had long held the ambition to build a Muslim place of worship in the heart of Turkey's largest city.

The mosque with its 30-meter high dome also dwarfs a monument dedicated to the nation and its founder Mustafa Kemal Ataturk.

"Taksim Mosque now occupies a prominent place among the symbols of Istanbul," Erdogan was quote as saying by BBC after the Friday prayers at the site, media reports quoted. "God willing, it will stay until the end of time," he added.

The opening of the mosque has sparked controversy as it lies at a place which is traditionally thought of as a symbol of secularism, an ideology asserted by Turkey’s founding father Mustafa Kemal Ataturk.

The inauguration of Taksim Square Mosque also coincided with the anniversary of the massive protests against the government, which started in the neighbouring Gezi Park eight years ago on May 28, 2013, due the construction plans of the government.

In 1994, when Erdogan became the mayor of Istanbul, he criticised the absence of a Muslim place of worship at Taksim Square while poiting out that the only place of worship there was an orthodox church.

"There wasn't even a prayer room and the faithful had to make do with praying on newspapers on the ground," Erdogan said at Friday's inauguration, media quoted.

At the event, a video dating back to 1994 was played showing Erdogan pointing to a spot and promising to build a mosque at the exact place where it now stands, according to media reports.

Erdogan's detractors have termed the building of the mosque as a blatant attempt to give religious tone to the square, and attack the legacy of Mustafa Kemal Ataturk, who established secularism in Turkey after the collapse of the Ottomon Empire.

Construction of the mosque started in February 2017 in a project launched by Erdogan and his Islamist-rooted AK Party. But it was mired by court battles and public debates.

Turkey's Anadolu news agency said the mosque complex has two minarets and can house 4,000 people at a time. It also has  an exhibition hall, a library, car park and soup kitchen, the agency added.