Started in A.D. 527 by Justinian in the first year of his reign, this former church represents an important stage in the process of Byzantine architecture, particularly in the support of the dome atop an octagonal base. The church took its name from two martyred Roman soldiers later elevated to the status of patron saints; the edifice later assumed the name of "Little Ayasofya" due to its resemblance to the Ayasofya, which was started in A.D. 532. The church was converted into a mosque in the 16th century by the chief eunuch under Beyazit II, who is buried in the garden. We know from the ancient historian Procopius that the interior of the church was covered in marble and mosaics; however, none of this remains. Opposite the entrance to the mosque is a medrese that encloses an uncharacteristically serene and leafy garden. An on-site eatery as well as teahouses share the arcade with a number of bookshops and calligraphy boutiques, offering genuine finds at some of the most competitive prices in the city.