Defterdar Mosque

The Defterdar Mosque, or the Defterdar Mahmut Efendi Mosque (), is 16th century Ottoman mosque located in Eyüp, Istanbul, Turkey. It was commissioned by Defterdar Nazlı Mahmut Efendi (c. 1500-1546) and built by architect Mimar Sinan in 1542 ("defterdar" was the head of the financial department in Ottoman Empire). Instead of a crescent, this mosque has "ink pot and pen" on top of its dome, representing the profession of the founder of the mosque. (since "defterdar" means chamberlain, literally it means defter:notebook + dar:suffix for "doer"). The original pair was broken by a storm in 1997. Ten years later, on 30 May 2007, a new inkpot and a pen assembled on top of the dome of the mosque.