Located between the districts of Cankurtaran and Kadırga, the Little Hagia Sophia mosque (Turkish: Küçük Ayasofya) was originally built as a church by the Byzantine Emperor Justinian and is one of the most important buildings of the early Byzantine period, in Istanbul.
Dedicated to St. Bacchus and St. Sergius the church was built in the year 530 and was converted to a mosque by Bayezid II after the Ottoman conquest of Istanbul. At that time the portico and madrassa were added to the church, now functioning as a mosque.
Built of stone and brick, still it is Istanbul’s oldest structure from the Byzantine period. The Hüseyin Ağa Madrassa has been restored for use by Turkish handicraft producers nowadays.