Facing one of the major gateways into the Grand Bazaar, this large mosque complex was built in Ottoman baroque style between 1748 and 1755. Construction was started by order of Mahmut I and finished during the reign of his successor, Osman III. Meticulously restored in recent years, it has a central prayer hall topped by one of the largest domes ever built in an Ottoman mosque, a unique polygonal rear courtyard and a külliye comprising medrese (seminary), imaret (soup kitchen), kütüphane (library) and türbe (tomb).
Though designed in the then highly fashionable and modern baroque style, the mosque has very strong echoes of Aya Sofya – specifically the lofty dome, colonnaded mezzanine galleries, broad band of calligraphy around the interior (in this case a marble relief of the Sura Al-Fath) and 174 windows topped with Roman arches. Despite its prominent position on the busy pedestrian route from Cağaloğlu Meydanı and Nuruosmaniye Caddesi to the bazaar, it is surprisingly peaceful and contemplative inside. The türbe contains Şehsuvar Sultan, mother of Osman III, and the library (being restored at the time of research) is home to more than 5000 handwritten and printed manuscripts. Visitor entry to the mosque is via the rear courtyard.