ANKARA, Turkey (AP) — Turkish President Recep Tayyip Erdogan formally opened a former Byzantine church in Istanbul as a mosque on Monday, four years after his government had designated it a Muslim house of prayer, despite criticism from neighboring Greece.

Turkey formally converted The Church of St. Saviour in Chora, known as Kariye in Turkish, into a mosque in 2020, soon after it similarly turned Istanbul’s landmark Haghia Sophia into a Muslim house of prayer.

Both conversions drew praise from Muslim faithful but criticism from Greece and other countries who had urged Turkey to protect the important Byzantine-era monuments. Both are listed as U.N. World Heritage Sites.

Like Haghia Sophia, which was a church for centuries and then a mosque for centuries more, the Chora had operated as a museum for decades before it was ordered turned into a mosque. The Chora’s formal launch as a mosque, however, was delayed as the structure then underwent restoration.

Erdogan on Monday remotely presided over a ceremony marking the opening of the Chora — as well as other recently-restored structures — from a conference hall at his palace complex in Ankara.

“May it bring good fortune,” Erdogan said during the televised event.

The church, situated near Istanbul’s ancient city walls, is famed for its elaborate mosaics and frescoes. It dates to the fourth century, although the edifice took on its current form in the 11th-12th centuries.

The structure served as a mosque during Ottoman rule before being transformed into a museum in 1945.

Greece had criticized the Turkish government’s decision to turn it back into a mosque, accusing Ankara of “insulting the character” of another World Heritage Site.

The decisions to transform Haghia Sophia and the Chora back into mosques were seen as moves geared to consolidate the conservative and religious support base of Erdogan’s ruling party amid an economic downturn.

In 2020, Erdogan joined hundreds of worshipers for the first Muslim prayers in Hagia Sophia in 86 years, brushing aside international criticism and calls for the monument to be kept as a museum. As many as 350,000 took part in the prayers outside the structure.