SS. Sergius and Bacchus, preserved as the mosque, Küçük Ayasofya

Küçük Ayasofya Mosque, the former Church of Saints Sergius and Bacchus, Istanbul, c. 536. speakers: Dr. Beth Harris and Dr. Steven Zucker

[0:00] [music]

Dr. Steven Zucker: [0:05] We’re in a mosque in Istanbul, the former Church of Saints Sergius and Bacchus.

Dr. Beth Harris: [0:11] It’s a very old church from the 6th century, the time of Justinian, who was also the patron of the great Church of Hagia Sophia, which is right nearby.

Dr. Zucker: [0:20] This was built just before Hagia Sophia, we believe, and some architectural historians think that this building functioned as a preliminary experiment for the larger structure.

Dr. Harris: [0:30] This is a centrally planned church, with a dome rising high over the center, and in that way, it is like Hagia Sophia, but Hagia Sophia combines that central plan with the length or longitudinal axis of a basilican plan.

Dr. Zucker: [0:44] The other main difference is with the dome. This smaller church has a very distinct dome. It’s faceted into 16 parts. You have an alternation of flat and concave surfaces.

Dr. Harris: [0:56] The flat surfaces of the dome open into windows.

Dr. Zucker: [1:00] Ironically, the real work of supporting the dome is being done by the concave surfaces, which follow down into these cleft piers.

Dr. Harris: [1:07] We can see in this early Byzantine period architects experimenting with how to support domed, centrally planned structures. We could see this if we think back to Ravenna, to the Church of San Vitale, the architects of the Byzantine Christian Empire searching for a new architectural vocabulary for their new empire.

Dr. Zucker: [1:28] This mosque was renovated numerous times. It’s gone through many changes. But there are still some interior forms that relate to the original structure. We can see that especially in the complicated entablature and in the columns on the first and the second floor.

[1:43] Clearly, we have references back to the classical tradition. But we also have changes that are part of this new Byzantine world. Probably most obvious is the very deep carving that creates this stark contrast between light and shadow.

Dr. Harris: [1:56] We see that deep carving also in Hagia Sophia and the capitals there. It’s almost as though a delicate piece of lace has been laid across and fluttering around the surface of the capital. And like in Hagia Sophia, when we look at the capitals here or we experience the space here, we have a sense of things billowing, of moving in and out.

Dr. Zucker: [2:17] This space is so different from the way it was described in the 6th century. The dome and the apses would have been covered largely with gold mosaic, and we think that some windows to one side of the church would have been doorways that would have opened up into another church right next door. A church to the saints Peter and Paul.

Dr. Harris: [2:34] Like Hagia Sophia, the walls were covered with very beautifully colored marble revetments, or marble panel. Its walls and its expanses would have felt very much like Hagia Sophia originally.

Dr. Zucker: [2:46] I’m really taken by the beautiful decorative qualities of these columns. The shafts are made of these amazingly variegated marbles in red and green. This is a beautiful church in its own right. It’s such a great testament to the ingenuity, the flexibility, the inventiveness of architects at this time.

Dr. Harris: [3:04] Along the interior frieze, we can see letters. This is an inscription honoring the emperor Justinian and his wife, the empress Theodora. Also, Saint Sergius is honored here as well.

Dr. Zucker: [3:14] Sergius and Bacchus were Roman soldiers who were martyred for their Christian beliefs and actually became the patron saints of the Christian Roman army.

Dr. Harris: [3:23] And apparently had very special significance to Justinian, the emperor. According to legend, he was accused of treason by the emperor at that time, who was Justin, his uncle, and he was sentenced to death. But luckily for Justinian, Saints Sergius and Bacchus appeared in a vision to the emperor Justin, and professed Justinian’s innocence.

[3:44] Justinian was not put to death and soon became the emperor himself.

Dr. Zucker: [3:47] He was so grateful, he said his first act would be to create a church honoring those two martyrs.

Dr. Harris: [3:53] We have this combination that we also see nearby in Hagia Sophia of Byzantine elements from the time of the Emperor Justinian, but also elements that are Islamic.

[4:03] We see Islamic inscriptions when we look at the apse. We also see a mihrab, the indentation in the apse of the church that indicates the direction of Mecca for Muslims to pray, and also the minbar, which on Fridays a sermon would be delivered from.

Dr. Zucker: [4:20] Both of those elements are skewed slightly to the right, because the church is oriented to the east but not oriented directly to Mecca.

Dr. Harris: [4:27] It already feels like a complicated space, but in a way, that shift in direction makes it even more complicated.

[4:33] [music]

Cite this page as: Dr. Steven Zucker and Dr. Beth Harris, "SS. Sergius and Bacchus, preserved as the mosque, Küçük Ayasofya," in Smarthistory, May 4, 2023, accessed July 13, 2024,