Mimar Sinan, the most renowned architect of the Ottoman Empire, spent many years in Edirne, working on his masterpiece - Selimiye Mosque. However, he was even more busy in this period as there are other buildings he erected in the city. Many of them are still standing, but they remain virtually unknown to the tourists arriving only to see Selimiye Mosque. Here is a story of Defterdar Mustafa Pasha Mosque, a forgotten creation of Sinan that reveals the architectural style of the grand master with all its beauty.

Defterdar Mustafa Pasha Mosque was built in 1576, as this date is provided of the building itself. Its name suggests that it was founded by the Ottoman Minister of Finance, called Mustafa Pasha. The term defter is derived from Greek diphthera (διφθέρα) meaning a book. It was later borrowed into Arabic daftar and subsequently into Persian and Turkish. Defterdar means a bookkeeper, because the ministers were in charge of the defters - tax registers. However, the list of defterdars of the period when the mosque was built does not provide us with a person bearing the name Mustafa, so he remains a mysterious sponsor of the mosque.

The building was erected from bricks and cut stones. There are two rows of bricks and a row of stones, alternately used on the eastern, western and southern sides. The northern side and the single minaret with one balcony were erected with regular cut blocks only. The main prayer hall is preceded with a three-bayed porch, covered with three small domes, made of lead sheets. The same material was used to cover the building's central dome and the pointed roof of the minaret.

The original dome of the mosque was destroyed in the 1752 earthquake. In 1870, the repair works were done by Hacı Ruşen Efendi, and the building was covered with a simple wooden roof instead. Only during the repairs made by the General Directorate of Foundations in 1953 and 1962, the dome, the portal and the windows were renovated, in accordance with the original design.

The interior of the mosque is lit by three rows of windows. There are nine window openings arranged in three rows on each of the facades. The windows in the lowest row are rectangular, and the upper two rows have windows with pointed arches. Inside, there is a simple prayer hall, with unplastered walls, so the layers of bricks and stones are clearly visible, creating a sombre atmosphere. There is a marble mihrab with muqarnas decoration and a stone mimbar to its right. The wooden lodge for women can be accessed via wooden stairs in the northwest part of the mosque.