Kalenderhane Mosque is a late 12th-century Byzantine church, generally identified as the Church of Theotokos Kyriotissa, standing right beside the eastern end of the Valens Aqueduct. After the conquest it was given to the Kalenderi dervishes, which is where its name comes from. Small as it is, its original marble revetments and the remarkable frescoes discovered during restoration make it one of Istanbul's hidden treasures for anyone interested in Byzantium.
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Church, dervish lodge, mosque
Excavations showed that a Roman bathhouse and then a series of earlier churches once occupied this site. The building you see today dates from the late 12th century and is identified by most scholars as the Church of Theotokos Kyriotissa, dedicated to the Virgin Mary. Its plan is a compact cross shape with a central dome and four arms.
During the Latin occupation after 1204, the church was used for a time by Latin clergy. After 1453 Mehmed II assigned it to the Kalenderi dervishes, giving it the name Kalenderhane, and it was later converted into a mosque with an added minaret.
The St Francis frescoes: an art-history surprise
During extensive restoration and research in the 1960s and 1970s, specialists uncovered 13th-century frescoes in one of the chapels depicting the life of St Francis of Assisi. Painted during the Latin period, they are considered one of the earliest known cycles devoted to the saint. According to published accounts, much of this material was removed for conservation and taken to the Istanbul Archaeology Museums.
Inside the mosque today, the coloured Byzantine marble panels and moulded arches still make its origins as a church unmistakable. The interior is plain, peaceful and in daily use for prayer.
What to see
- Original marble revetment: Coloured Byzantine marble panels on the walls.
- The cross-shaped interior: A compact, harmonious space under a central dome.
- Brickwork outside: Typical Byzantine bands of stone and brick and arched details.
- The aqueduct next door: Step outside and the eastern end of the Valens Aqueduct is right beside you.
- The neighbourhood: The back streets of Istanbul University and the student quarter of Vezneciler.
Visiting tips
Kalenderhane serves as a neighbourhood mosque, so its doors may be locked outside prayer times; arriving shortly before or after a prayer gives you the best chance of seeing inside. Keep your voice low and follow our mosque etiquette guide.
To compare other Byzantine churches that became mosques, add the Zeyrek Mosque and the Little Hagia Sophia near our hotel to your plans. Our Byzantine Istanbul route brings these sites together.
Getting there from Sareban Hotel
From the hotel, walk along Divanyolu past Beyazıt Square, then continue along the western side of Istanbul University towards Vezneciler; the mosque sits just south of the eastern end of the Valens Aqueduct. By public transport, take the T1 tram to Beyazıt-Kapalıçarşı or Laleli-Üniversite and walk a short distance. Vezneciler metro station is also very close.
Frequently asked questions
Was Kalenderhane Mosque originally a church?
Yes. It is a late 12th-century Byzantine church, generally identified as the Church of Theotokos Kyriotissa, converted into a mosque after the Ottoman conquest.
Where does the name Kalenderhane come from?
Mehmed II gave the building to the Kalenderi dervishes, and it has carried their name ever since.
Can I see the St Francis frescoes in the mosque?
According to published accounts, much of the fresco material was moved to the Istanbul Archaeology Museums for conservation. In the mosque today you mainly see the marble revetment and architectural details.
