The location of the complex had been probably a holy spring and (35) a religious center in the Byzantine era. Merkez Efendi used here as a reclusion house. The lodge which had been built by the efforts of Merkez Efendi’s followers was rebuilt by Mimar Sinan by the order of Şah Sultan, sister of Sultan Suleiman the Magnificent, in 1552-1572. The complex holds a mosque, a reclusion house, dervish rooms, rooms for domestic use (Harem and Selamlık), a kitchen, a lunchroom, a Turkish bath, the tomb and the cemetery. The building complex has undergone many essential alterations during various renovations throughout the history. A house of Qur’an recital, a fountain and an ablution facility were added to the complex during these renovations. An epitaph written by Yesarizade Mustafa İzzet Efendi (died in 1849) on the pediment of the main gate informs the visitors that the complex was repaired by Mahmud II. Following the legislation of 1925 to close dervish lodges down, the complex has begun to serve only as a mosque. The complex took its final form after the restorations carried out by Zeytinburnu Municipality in 1965, 2010-2013. Harem building serves as a center for The Union of Turkish World Municipalities today.