Sedefkâr Mehmed Ağa (?-1622/23)
Sadefkâr Mehmed Ağa is renowned as the architect who built the Sultan Ahmed Mosque (the “Blue Mosque”) in Istanbul. According to the biographer Cafer Effendi, he was believed to be Albanian and brought from Rumeli to Istanbul in 1562. During the last period of the reign of Kanuni Sultan Süleyman I (1520-1566), Mehmed served as a cadet (Acemi Oğlan) for five years, and began working as a garden keeper at the tomb of Sultan Süleyman. During his service, Mehmed audited engineering classes. Getting permission from his teachers, he started to join classes and studied architecture with Mimar Sinan, Mimar Davud, and Mimar Dalgıç Ahmed Ağa for 20 years. He also worked in mother-of-pearl inlay with Halife Üstad Muhammed and became a specialist (Sedefkâr). Mehmed was a pupil of the architect Sinan, becoming his First Assistant in charge of the office in the absence of Sinan. In January 1586, he was appointed to complete the Muradiye Mosque in Manisa, a construction project started by his master. Mimar Sinan advised Mehmed to present a reading desk inlaid with mother-of-pearl to Sultan Murad III (1546-1595). Mehmed was given the position of gate-keeper in the Topkapı Palace.

In 1590, Mehmed was appointed to be a Harem guard (Kulle Sofisi / Harem Muhafızı) and escorted a criminal to Egypt, then visited Hicaz, Palestine and Syria. After coming back to Istanbul, he was sent to inspect cities and castles in the Balkans, by order of the Sultan. He had opportunities to visit Selanik, Albania, Malta, Spain, Bosnia, Frengistan, Budin, Erdel, Eflak, Boğdan, Kırım, Kefe, Silistre, Niğbolu, Semendire and Belgrade. Mehmed was promoted to Chief Bailiff (Muhzırbaşılık) of Istanbul in 1591. In the same year, he began serving Hüsrev Paşa as a lieutenant governor (Müsellim) of Diyarbakır and an inspector of works. After returning to Istanbul as a chamberlain (Kapu Kethüdası), he was sent to Damascus as a lieutenant governor of Hüsrev Paşa. In 1597, Mehmed returned to Istanbul and was appointed to a Master of the Waterways by Sultan Mehmed III, and worked in this position for 8 years. Mehmed was succeeded as a royal architect by Dalgıç Ahmed Ağa and became the Chief Imperial Architect (Hassa Mimarbaşı) in 1606. Sultan Ahmed I (1603-1617) ordered him to build the Sultan Ahmed Mosque. He completed it between 1609 and 1616. Mehmed Ağa had a book on architecture theory written for him by Cafer Efendi. In this book, he explained his methods of work and the architectural training of the period. Mehmed Ağa built 12 major and small mosques (mescit), eight tombs, two madrasahs, two hamams, three palaces and kiosks, one bridge, more than 200 palace and mosque fountains, 11 public fountains (sebil) and one caravanserai. After the death of Mehmed Ağa in 1622/ 23, Kasım Ağa was appointed as the Chief Imperial Architect.