Which Byzantine church in Istanbul is also known as the Church of the Theotokos Kyriotissa?

Kalenderhane Mosque in Istanbul is identified with the Byzantine Church of the Theotokos Kyriotissa.

The church stood near the Valens Aqueduct in Constantinople and was dedicated to the Virgin Mary under the title Kyriotissa, often translated as “Lady.” Its surviving structure is an important example of a Middle Byzantine cross-in-square church.

Archaeological and architectural studies have identified several construction phases at the site. The present church is generally dated to the later Byzantine period, although earlier buildings occupied the location and the precise chronology has been debated.

After the Ottoman conquest, the building was converted into a mosque and acquired its modern name, Kalenderhane. It is distinct from Istanbul’s Bodrum Mosque, which is associated with the Myrelaion, and from Fethiye Mosque, the former Pammakaristos Church.