Essential Architecture-  Turkey

SS. Sergius and Bacchus, Kutchuk Aya Sofia




Istanbul, Turkey






Brick, originally tile roof, later lead roof.


Present-day Mosque, former Church
The church of SS. Sergius and Bacchus in Constantinople is dedicated to two Roman soldiers who were tortured to death in 303. According to a legend, Bacchus was flogged to death first, while Sergius survived and was brought to the fort at Resafa, not far from the Euphrates, where he was again tortured. Here, the spirit of Bacchus appeared to him, and encouraged him to remain steadfast in his Christian beliefs. Sergius was in the end beheaded. The two soldiers were recognized as the patron saints of all soldiers in the Roman and Byzantine armed forces.

This cult was immensely popular in Syria, and soon spread to other parts of the Roman empire. The emperor Justinian was one of the most ardent devotees. As a youth, he had been condemned to death because he was believed to have plotted against the emperor Anastasius I (491-518), but the twin saints had, according to a legend, in a dream appeared to the ruler, who had now understood that Justinian was innocent -or that God had greater plans with the man- and had released the young man.

It comes as no surprise that Justinian dedicated a church to SS. Sergius and Bacchus. The grounds on which the new sanctuary was built, were not far from the Hormisdas Palace, where Justinian used to live - a bit to the west, to be precise, on the point where the Sea Walls, would have been broken by the Hippodrome if that would have been longer. Construction started as soon as Justian ascended the throne in 527. The architect was Anthemius of Tralles, who was better known as a mathematician and the author of a book on burning mirrors, the Paradoxographia, (which was to become notorious because it is the origin of the fairy tale that Archimedes had constructed burning mirrors during the siege of Syracuse).

It was a complex project, because a second church, which was designed as a basilica (with three straight naves) was very close to it, and in fact shared the entrance (narthex) with the Church of SS. Sergius and Bacchus. It is not recorded to whom this second church was dedicated, and no traces of it are left. Construction took several years, but the project was finished before 536. The significance of this building is that its octogonal design was later, on a much larger scale, reused by Anthemius when he and Isidore of Miletus built the Church of the Divine Wisdom, the Hagia Sophia. An old description of the SS. Sergius and Bacchus is given by Procopius:

Justinian built a shrine to the famous Saints Sergius and Bacchus, and then also another shrine which stood at an angle to this one. These two churches do not face each other, but stand at an angle to one another, being at the same time joined to each other and rivalling each other; and they share the same entrances and are like each other in all respects, even to the open spaces by which they are surrounded; and each of them is found to be neither superior nor inferior to the other either in beauty or in size or in any other respect. Indeed each equally outshines the sun by the gleam of its stones, and each is equally adorned throughout with an abundance of gold and teems with offerings. In just one respect, however, they do differ. For the long axis of one of them is built straight, while in the other church the columns stand for the most part in a semi-circle. But whereas they possess a single colonnaded stoa, called a narthex because of its great length, for each one of their porches, they have their propylaea entirely in common, and they share a single court, and the same doors leading in from the court, and they are alike in that they belong to the Palace.
[Procopius, Buildings, 1.4.3-7]

The dome is very remarkable, because it consists of eight flat and eight concave sections, which rest on eight piers. This is unique, but it might well have become extremely popular. Many churches in this age were very innovative and experimental; the architects were still looking for new forms. Eventually, the dome of the Hagia Sophia was to receive a different design, whoich became the new standard.

The church was converted into a mosque in the first years of the sixteenth century and is now known as the Küçük Ayasofya, the "Little Hagia Sofia".

Capital in the Church of SS. Sergius and Bacchus. Photo Marco Prins.
Text quoted from-
Byzantine Churches in Constantinople, Their History and Architecture.
MACMILLAN AND CO., Limited, London, 1912.
by Alexander Van Millingen and Ramsay Traquair and W. S. George and A. E. Henderson.

The Church of SS. Sergius and Bacchus, Kutchuk Aya Sofia


On the level tract beside the Sea of Marmora, to the south of the Hippodrome, and a few paces to the north-west of Tchatlady Kapou, stands the ancient church of SS. Sergius and Bacchus. It is commonly known as the mosque Kutchuk Aya Sofia, Little S. Sophia, to denote at once its likeness and its unlikeness to the great church of that name. It can be reached by either of the two streets descending from the Hippodrome to the sea, or by taking train to Koum Kapou, and then walking eastwards for a short distance along the railroad. There can be no doubt in regard to its identity. For the inscription on the entablature of the lower colonnade in the church proclaims the building to be a sanctuary erected by the Emperor Justinian and his Empress Theodora to the honour of the martyr Sergius. The building stands, moreover, as SS. Sergius and Bacchus stood, close to the site of the palace and the harbour of Hormisdas.81 When Gyllius visited the city the Greek community still spoke of the building as the church of SS. Sergius and Bacchus—'Templum Sergii et Bacchi adhuc superest, cujus nomen duntaxat Graeci etiam nunc retinent.



SS. Sergius and Bacchus. Interior, looking north-west

SS. Sergius and Bacchus.
Interior, looking north-west


The foundations of the church were laid in 527, the year of Justinian's accession,83 and its erection must have been completed before 536, since it is mentioned in the proceedings of the Synod held at Constantinople in that year.84 According to the Anonymus, indeed, the church and the neighbouring church of SS. Peter and Paul were founded after the massacre in the Hippodrome which suppressed the Nika Riot. But the Anonymus is not a reliable historian.

The church did not stand alone. Beside it and united with it, Justinian built also a church dedicated to the Apostles Peter and Paul,86 so that the two buildings formed a double sanctuary, having a common court and a continuous narthex. They were equal in size and in the richness of the materials employed in their construction, and together formed one of the chief ornaments of the palace and the city. There was, however, one striking difference between them; SS. Sergius and Bacchus was a domical church, while SS. Peter and Paul was a basilica. Styles of ecclesiastical architecture destined soon to blend together in the grandeur and beauty of S. Sophia were here seen converging towards the point of their union, like two streams about to mingle their waters in a common tide. A similar combination of these styles occurs at Kalat-Semân in the church of S. Symeon Stylites, erected towards the end of the fifth century, where four basilicas forming the arms of a cross are built on four sides of an octagonal court.

The saints to whom the church was dedicated were brother officers in the Roman army, who suffered death in the reign of Maximianus,88 and Justinian's particular veneration for them was due, it is said, to their interposition in his behalf at a critical moment in his career. Having been implicated, along with his uncle, afterwards Justin I., in a plot against the Emperor Anastasius, he lay under sentence of death for high treason; but on the eve of his execution, a formidable figure, as some authorities maintain,89 or as others affirm, the saints Sergius and Bacchus, appeared to the sovereign in a vision and commanded him to spare the conspirators. Thus Justinian lived to reach the throne, and when the full significance of his preservation from death became clear in the lustre of the imperial diadem, he made his deliverers the object of his devout regard. Indeed, in his devotion to them he erected other sanctuaries to their honour also in other places of the Empire.90 Still this church, founded early in his reign, situated beside his residence while heir-apparent, and at the gates of the Great Palace, and withal a gem of art, must be considered as Justinian's special thankoffering for his crown.

With the church of SS. Sergius and Bacchus was associated a large monastery known, after the locality in which it stood, as the monastery of Hormisdas. It was richly endowed by Justinian.




There is some obscurity in regard to the church of SS. Peter and Paul. According to Theophanes,92 the first church in Constantinople built in honour of those apostles was built at the suggestion of a Roman senator Festus, who on visiting the eastern capital, in 499, was astonished to find no sanctuary there dedicated to saints so eminent in Christian history, and so highly venerated by the Church of the West. As appears from a letter addressed in 519 to Pope Hormisdas by the papal representative at the court of Constantinople, a church of that dedication had been recently erected by Justinian while holding the office of Comes Domesticorum under his uncle Justin I. 'Your son,' says the writer, 'the magnificent Justinian, acting as becomes his faith, has erected a basilica of the Holy Apostles, in which he wishes relics of the martyr S. Laurentius should be placed.' 'Filius vester magnificus vir Justinianus, res convenientes fidei suae faciens, basilicam sanctorum Apostolorum in qua desiderat Sancti Laurentii martyris reliquias esse, constituit.'93 We have also a letter to the Pope from Justinian himself, in which the writer, in order to glorify the basilica which he had built in honour of the apostles in his palace, begs for some links of the chains which had bound the apostles Peter and Paul, and for a portion of the gridiron upon which S. Laurentius was burnt to death. The request was readily granted in the same year.


The description of the basilica, as situated in the palace then occupied by Justinian, leaves no room for doubt that the sanctuary to which the letters just quoted refer was the church of SS. Peter and Paul which Procopius describes as near the palace of Hormisdas. In that case the church of SS. Peter and Paul was built before the church of SS. Sergius and Bacchus, for the inscription on the entablature in the latter church, not to mention Cedrenus, distinctly assigns the building to the time when Justinian and Theodora occupied the throne. This agrees with the fact that Procopius95 records the foundation of SS. Peter and Paul before that of SS. Sergius and Bacchus, and if this were all he did the matter would be clear. But, unfortunately, this is not all Procopius has done. For after recording the erection of SS. Sergius and Bacchus, he proceeds to say that Justinian subsequently joined another church,96 a basilica, to the sanctuary dedicated to those martyrs, thus leaving upon the reader's mind the impression that the basilica was a later construction.


To whom that basilica was consecrated Procopius does not say. Was that basilica the church of SS. Peter and Paul which Procopius mentioned before recording the erection of SS. Sergius and Bacchus? Is he speaking of two or of three churches? The reply to this question must take into account two facts as beyond dispute: first, that the church of SS. Peter and Paul, as the letters cited above make clear, was earlier than the church of SS. Sergius and Bacchus; secondly, that the basilica united to the latter sanctuary was dedicated to the two great apostles; for scenes which, according to one authority, occurred in S. Peter's took place, according to another authority,98 in the church of SS. Sergius and Bacchus. In the face of these facts, Procopius is either mistaken in regard to the relative age of the two sanctuaries, or he has not expressed his meaning as clearly as he might have done. To suppose that two sanctuaries dedicated to the great apostles were built by Justinian within a short time of each other in the same district, one within the palace, the other outside the palace, is a very improbable hypothesis. The question on which side of SS. Sergius and Bacchus the basilica of SS. Peter and Paul stood, seems decided by the fact that there is more room for a second building on the north than on the south of Kutchuk Agia Sofia.


Furthermore, there are traces of openings in the north wall of the church which could serve as means of communication between the two adjoining buildings. Ebersolt, however, places SS. Peter and Paul on the south side of SS. Sergius and Bacchus.99 A remarkable scene was witnessed in the church in the course of the controversy which raged around the writings known in ecclesiastical history as 'The Three Chapters,' the work of three theologians tainted, it was alleged, with the heretical opinions of Nestorius. Justinian associated himself with the party which condemned those writings, and prevailed upon the majority of the bishops in the East to subscribe the imperial decree to that effect. But Vigilius, the Pope of the day, and the bishops in the West, dissented from that judgment, because the authors of the writings in question had been acquitted from the charge of heresy by the Council of Chalcedon.


To condemn them after that acquittal was to censure the Council and reflect upon its authority. Under these circumstances Justinian summoned Vigilius to Constantinople in the hope of winning him over by the blandishments or the terrors of the court of New Rome. Vigilius reached the city on the 25th of January 547, and was detained in the East for seven years in connection with the settlement of the dispute. He found to his cost that to decide an intricate theological question, and above all to assert 'the authority of S. Peter vested in him' against an imperious sovereign and the jealousy of Eastern Christendom, was no slight undertaking. Pope and Emperor soon came into violent collision, and fearing the consequences Vigilius sought sanctuary in the church of S. Peter100 as he styles it, but which Byzantine writers101 who record the scene name S. Sergius.



SS. Sergius and Bacchus. Capital.

SS. Sergius and Bacchus.

S. John of the Studion. Capital in the Narthex.

S. John of the Studion.
Capital in the Narthex.


Justinian was not the man to stand the affront. He ordered the praetor of the city to arrest the Pope and conduct him to prison. But when that officer appeared, Vigilius grasped the pillars of the altar and refused to surrender. Thereupon the praetor ordered his men to drag the Pope out by main force. Seizing Vigilius by his feet, holding him by his beard and the hair of his head, the men pulled with all their might, but they had to deal with a powerful man, and he clung fast to the altar with an iron grip. In this tug-of-war the altar at length came crashing to the ground, the Pope's strong hands still holding it tight. At this point, however, the indignation and sympathy of the spectators could not be restrained; the assailants of the prostrate prelate were put to flight, and he was left master of the situation. Next day a deputation, including Belisarius and Justin, the heir-apparent, waited upon Vigilius, and in the emperor's name assured him that resistance to the imperial will was useless, while compliance with it would save him from further ill-treatment. Yielding to the counsels of prudence, the Pope returned to the palace of Placidia,102 the residence assigned to him during his stay in the capital.

Probably at this time arose the custom of placing the churches of SS. Peter and Paul, and SS. Sergius and Bacchus at the service of the Latin clergy in Constantinople, especially when a representative of the Pope, or the Pope himself, visited the city. The fact that the church was dedicated to apostles closely associated with Rome and held in highest honour there, would make it a sanctuary peculiarly acceptable to clergy from Western Europe. This, however, did not confer upon Roman priests an exclusive right to the use of the building, and the custom of allowing them to officiate there was often more conspicuous in the breach than in the observance. Still the Roman See always claimed the use of the church, for in the letter addressed in 880 by Pope Julius VIII. to Basil I., that emperor is thanked for permitting Roman clergy to officiate again in SS. Sergius and Bacchus according to ancient custom: 'monasterium Sancti Sergii intra vestram regiam urbem constitutum, quod sancta Romana Ecclesia jure proprio quondam retinuit, divina inspiratione repleti pro honore Principis Apostolorum nostro praesulatui reddidistis.


The most distinguished hegoumenos of the monastery was John Hylilas, better known, on account of his learning, as the Grammarian, and nicknamed Lecanomantis, the Basin-Diviner, because versed in the art of divination by means of a basin of polished brass. He belonged to a noble family of Armenian extraction, and became prominent during the reigns of Leo V., Michael II., and Theophilus as a determined iconoclast. His enemies styled him Jannes, after one of the magicians who withstood Moses, to denote his character as a sorcerer and an opponent of the truth. Having occasion, when conducting service in the imperial chapel to read the lesson in which the prophet Isaiah taunts idolaters with the question, 'To whom then will ye liken God, or to what likeness will ye compare him?' John, it is said, turned to Leo V., and whispered the significant comment, 'Hearest thou, my lord, the words of the prophet? They give thee counsel.' He was a member of the Commission charged by that emperor to collect passages from the Holy Scriptures and the Fathers of the Church that condemned the use of images in worship. Prominent iconodules were interned in the monastery of Hormisdas in the hope that he would turn them from the error of their ways by his arguments and influence. He directed the education of Theophilus and supported the iconoclastic policy pursued by that pupil when upon the throne.


Theophilus appointed his tutor syncellus to the Patriarch Antony, employed him in diplomatic missions,104 and finally, upon the death of Antony, created him patriarch. The name of John can still be deciphered under somewhat curious circumstances, in the litany which is inscribed on the bronze doors of the Beautiful Gate at the south end of the inner narthex of S. Sophia. When those doors were set up in 838, Theophilus and his empress had no son, and accordingly, in the threefold prayer inscribed upon the doors, the name of John was associated with the names of the sovereigns as a mark of gratitude and esteem. But in the course of time a little prince, to be known in history as Michael III., was born and proclaimed the colleague of his parents. It then became necessary to insert the name of the imperial infant in the litany graven on the Beautiful Gate of the Great Church, and to indicate the date of his accession. To add another name to the list of names already there was, however, impossible for lack of room; nor, even had there been room, could the name of an emperor follow that of a subject, though that subject was a patriarch. The only way out of the difficulty, therefore, was to erase John's name, and to substitute the name of the little prince with the date of his coming to the throne; the lesser light must pale before the greater. This was done, but the bronze proved too stubborn to yield completely to the wishes of courtiers, and underneath Michael's name has kept fast hold of the name John to this day. The original date on the gate also remains in spite of the attempt to obliterate it.

SS. Sergius and Bacchus was one of the sanctuaries of the city to which the emperor paid an annual visit in state.105 Upon his arrival at the church he proceeded to the gallery and lighted tapers at an oratory which stood in the western part of the gallery, immediately above the Royal Gates, or principal entrance to the church. He went next to the chapel dedicated to the Theotokos, also in the gallery, and after attending to his private devotions there, took his place in the parakypticon (ἐν τῷ παρακυπτικῷ τοῦ θυσιαστηρίου), at the north-eastern or south-eastern end of the gallery, whence he could overlook the bema and follow the public service at the altar.106 In due course the Communion elements were brought and administered to him in the chapel of the Theotokos; he then retired to the metatorion (a portion of the gallery screened off with curtains), while the members of his suite also partook of the Communion in that chapel. At the close of the service he and his guests partook of some light refreshments, biscuits and wine, in a part of the gallery fitted up for that purpose, and thereafter returned to the palace.


Architectural Features


In the description of the architectural features of the church and for the plans and most of the illustrations in this chapter I am under deep obligation to Mr. A. E. Henderson, F.S.A. The information gained from him in my frequent visits to the church in his company, and from his masterly article on the church which appeared in the Builder of January 1906, has been invaluable.


In design the church is an octagonal building roofed with a dome and enclosed by a rectangle, with a narthex along the west side. This was a favourite type of ecclesiastical architecture, and is seen also in another church of the same period, San Vitale of Ravenna, in which Justinian and Theodora were interested. There, however, the octagonal interior is placed within an octagonal enclosure. The adoption of a rectangular exterior in the Constantinopolitan sanctuary is a characteristic Byzantine feature.107 S. Vitale was founded in 526, a year before SS. Sergius and Bacchus.


SS. Sergius and Bacchus, from the south-east.

E. M. Antoniadi.

SS. Sergius and Bacchus,
from the south-east.

SS. Sergius and Bacchus. In the Gallery over the Narthex.

SS. Sergius and Bacchus.
In the Gallery over the Narthex



As an examination of the plan will show, the architect's design has not been followed with strict accuracy, and the result is that both the enclosing square and the interior octagon are very irregular figures. Furthermore, the two portions of the building have not the same orientation, so that the octagon stands askew within its rectangular frame. How this lack of symmetry should be explained, whether due to sloven work or the result of the effort to adapt the church to the lines of the earlier church of SS. Peter and Paul, with which it was united, is difficult to decide.


The court which stands before the Turkish portico in front of the west side of the building represents the old atrium of the church, and to the rear of the portico is still found the ancient narthex. At the south end of the narthex is a stone staircase leading to the gallery. The arch at the foot of the staircase is built of fragments from the old ciborium or eikonostasis of the church. The great height (0.24 metre or 9 inches) of the steps is found, according to Mr. Antoniadi, also in S. Sophia.


The exterior walls, which are mostly in brick and rubble masonry, exhibit poor workmanship, and have undergone considerable repair, especially on the east. On the south there are two thicknesses of walling. The outer thickness has arched recesses at intervals along its length, corresponding to openings in the inner thickness, and thus while buttressing the latter also enlarges slightly the area of the church. The length of the rectangular enclosure from west to east is 101 feet, with an average breadth of 7712 feet from north to south, excluding the recesses in the latter direction.


All the windows of the church have been altered by Turkish hands, and are rectangular instead of showing semicircular heads.


The passage intervening between the rectangular enclosure and the octagon is divided into two stories, thus providing the church with an ambulatory below and a gallery above.


The domed octagon which forms the core of the building stands at a distance of some 1812 feet from the rectangle within which it is placed. It measures 5312 feet by 5012 feet. The eight piers at its angles rise to a height of 3312 feet from the floor to the springing of the dome arches. The archways thus formed, except the bema arch, are filled in with two pairs of columns in two stories set on the outer plane of the piers. The lower colonnade is surmounted, after the classic fashion, by a horizontal entablature profusely carved while the upper columns are bound by arches, thus making seven sides of the octagon a beautiful open screen of fourteen columns and as many triple arcades, resplendent with marbles of various hues and rich with carved work. The mass of the piers is relieved by their polygonal form, a fluted cymatium along their summit, and a repeating design of a flower between two broad leaves below the entablature. Though the flower points upwards it has been mistaken for a cluster of grapes. At the four diagonal points the sides of the octagon are semicircular, forming exhedrae, an arrangement which gives variety to the lines of the figure, widens the central area, secures more frontage for the gallery, and helps to buttress the dome. The same feature appears in S. Sophia, whereas in San Vitale all the sides of the octagon, excepting the eastern side, are semicircular. The extension of the interior area of a building (square or octagonal) by means of niches at the angles or in the sides, or both at the angles and in the sides, was a common practice.


There is considerable difference in the size of the piers and the dome arches. The eastern piers stand farther apart than their companions, and consequently the arch over them, the triumphal arch of the sanctuary, is wider and loftier than the other arches. The bays to the north-east and the south-east are also wider than the bays at the opposite angles. The apse is semicircular within, and shows three sides on the exterior. As in S. Sophia and S. Irene, there is no prothesis or diaconicon.


The pairs of columns, both below and above, are alternately verd antique and red Synnada marble, resting on bases of the blue-veined white marble from the island of Marmora. The capitals on the lower order are of the beautiful type known as the 'melon capital,' a form found also in San Vitale at Ravenna and in the porch of S. Theodore in Constantinople. The neckings are worked with the capitals, and enriched by 'egg-and-dart' pointing upwards. In the centre of the capitals was carved the monogram of Justinian or that of Theodora. Most of the monograms have been effaced, but the name of the empress still appears on the capital of the western column in the south bay, while that of Justinian is found on the first capital in the south-western bay; on both capitals in the north-western bay, accompanied by the title Basileus; and, partially, on the last capital in the north-eastern bay.


In the soffit of the architrave are sunk panels of various patterns, the six-armed cross occurring twice. The beadings of the fasciae are enriched with the designs commonly known as 'rope,' 'bead-and-reel,' 'egg-and-dart,' and again 'bead-and-reel.


The frieze is in two heights. The lower portion is a semicircular pulvinar adorned with acanthus leaves, deeply undercut; the upper portion is occupied by a long inscription in raised ornamental letters to the honour of Justinian, Theodora, and S. Sergius. The cornice is decorated with dentils, 'bead-and-reel,' projecting consols, 'egg-and-dart,' and leaves of acanthus.


The inscription may be rendered thus: Other sovereigns, indeed, have honoured dead men whose labour was useless. But our sceptred Justinian, fostering piety, honours with a splendid abode the servant of Christ, Creator of all things, Sergius; whom nor the burning breath of fire, nor the sword, nor other constraints of trials disturbed; but who endured for the sake of God Christ to be slain, gaining by his blood heaven as his home. May he in all things guard the rule of the ever-vigilant sovereign, and increase the power of the God-crowned Theodora whose mind is bright with piety, whose toil ever is unsparing efforts to nourish the destitute.


 The inscription is not mere flattery to the founders of the church. Justinian and Theodora were devout after the fashion of their day, and took a deep interest in the poor. The empress erected an asylum for fallen women, hostels for strangers, hospitals for the sick, and homes for the destitute. 'On the splendid piece of tapestry embroidered in gold which formed the altar cloth of S. Sophia, she was represented with Justinian as visiting hospitals and churches.


Church of SS. Sergius and Bacchus. Inscription on the Frieze in the Church.

Fig. 20.


To the rear of the southern straight side of the octagon two columns stand under the gallery, with wide fillets worked on both sides of their bases, shafts, and capitals, showing that a frame of stone or wood was once affixed to them. The capitals are of the ordinary cushion type and bear on opposite faces the monograms Justinian, Basileus.




SS. Sergius and Bacchus. The Interior, Looking north-east.

SS. Sergius and Bacchus.
The Interior, Looking north-east.

SS. Sergius and Bacchus. Portion of the Entablature.

SS. Sergius and Bacchus.
Portion of the Entablature.


Two feet above the cornice, or twenty feet from the floor of the church, the level of the gallery is reached. Here the columns are smaller than those below, and are bound together by arches instead of by an architrave. Their capitals represent the type known as the 'Pseudo-Ionic' or cushion capital, in view of its broad head. It appears appropriately here as the form of capital required to carry the impost of an arch upon a capital. At one time, indeed, that demand was met by placing upon the capital a distinct block of stone, a fragment, so to speak, of the horizontal architrave. It is the device adopted in San Vitale at Ravenna, S. Demetrius of Salonica, and elsewhere, but never it would seem in Constantinople, except in the underground cisterns of the city. It was, however, too inartistic to endure, and eventually was superseded by capitals with a broad flattened head on which the wide impost of an arch could rest securely.

A free form of acanthus, deeply undercut on the face towards the central area of the church, covers the capitals, and in the centre of that face, on all the capitals except the eighth (counting from the north-east) is carved the monogram of the title Basileus, or of Justinian, or of Theodora.In the south side of the gallery stand two columns corresponding to the two columns in the aisle below. They are poor in design and not original. The western capital is 'Pseudo-Ionic, with a plain cross on the northern face. The eastern capital is in the basket form with roundels on the four faces. Two additional columns are found in the western portion of the gallery.


They are of verd antique and larger than the other columns in this story of the church, and have sunk crosses in them. The splendour of the interior decoration has certainly been dimmed, for the walls of the edifice once gleamed with marbles and glittered with mosaics. 'By the sheen of its marbles,' says Procopius,114 'it was more resplendent than the sun, and everywhere it was filled profusely with gold.' When Ferguson examined the building, remains of frescoes or of mosaics, which have disappeared since his time, could be distinguished in the narthex. The soffit, both of the upper and of the lower cymatium on the piers, projects sufficiently to admit the application of the customary marble incrustation. The proportions of the building are marred by the boarded floor which rises seventeen centimeters above the original pavement, disguising the real elevation of the dome and of the columns in the lower colonnade. But notwithstanding all changes for the worse the building is still a beautiful structure.


Very effective especially is the happy combination of the various lines and forms here brought together—the rectilinear and the semicircular sides of the octagon, the octagonal fabric and the round dome that crowns it, the horizontal entablature stretched along the summit of the lower story of columns and the arches that leap from column to column in the gallery. This harmonious variety of form has also a historical significance. An old order in architecture and a new order here meet and embrace before the earlier, having served its age, passes away and the later comes triumphant to fill another era of the world with fresh beauties. Here in the tide of time we look before and after.

To the student of architecture the dome of this church is specially interesting. In the application of the dome to the octagon no pendentives are employed. The octagon is carried up to the base of the dome, which is built in sixteen longitudinal compartments that impinge upon one another and form groins giving to the dome its strength and sweep. On the groins is a plaster moulding, probably Byzantine. The eight compartments directly above the dome arches are flat, and flush with the inner face of the octagon, and in each of them is a semicircular-headed window. They rise perpendicular to a point a little above the windows, and then curve with a radius to the centre of the dome.



The Baptistery, S. Sophia, from the east..

The Baptistery, S. Sophia, from the east.

The Baptistery, S. Sophia. The Interior, looking west.

The Baptistery, S. Sophia.
The Interior, looking west.


Church of SS. Sergius and Bacchus. Exterior View of the Dome.

Fig. 21.—View of the Exterior of the Dome of SS. Sergius and Bacchus


On the other hand the eight compartments directly above the angles of the octagon are narrower than the preceding compartments; they have no windows, and, what is of special importance to note, they are deeply concave.115 Such marked hollowness is found in later domes as a decorative feature, but here it is primarily and supremely a constructive device. By its means the concave compartments are set slightly back from the octagon's inner face, leaving, at the springing line, portions of the wall-head to appear as little flat ledges on each side of the angles.


This is a most skilful expedient, and compares favourably with the methods employed elsewhere to apply the dome to the octagon.116 In the octagonal church of S. Lorenzo at Milan the octagon is turned into the circle by the introduction of squinches. In San Vitale a considerable walling is built between the line of the octagon and the springing line of the dome, while the bed for the dome is formed by introducing, in the space over the angles of the octagon, niches which are worked above to the circle on plan. On the other hand, it is interesting to compare with these methods the method employed in the baptistery of S. Sophia, now a Sultan's Turbé, near the southern entrance to the inner narthex. Although the walls of the building describe a square on the exterior, they form an octagon on the interior with semicircular bays at the diagonals, as in SS. Sergius and Bacchus. But in the application of the dome the true pendentive is used. The baptistery was erected shortly before S. Sophia, and in view of the erection of the great church.

The curvature of the dome of SS. Sergius and Bacchus has three zones, which have respectively a radius of m. 8, (drawn from the centre of the octagon), m. 31⁄4, and m. 91⁄2, (centre about m. 2, below the springing of the dome). The first extends to a point a little above the heads of the dome windows; the second about m. 2 higher; the third to the crown of the dome. The groins stop short a little below the dome's apex, where they are arched into one another, leaving a saucer-shaped crown now capped by a Turkish finial. The dome is covered with lead, and presents an undulating surface owing to the protuberance of its eight concave compartments.

The system of weighting and buttressing the dome displays great skill, and will be best understood by studying Mr. Henderson's geometrical and constructive sections of the systems (Figs. 28, 29).


At east end of south aisle.

At east end of south aisle.

In the gallery.

In the gallery.

Fig. 22.—Brick Stamps in SS. Sergius and Bacchus.
(From rubbings by Mr. A. E. Henderson.)


Ground Plan (looking up) and Gynaeceum Plan (looking up).

Fig. 23.

Fig. 24.




Plan at base of Dome (Cross Section), Transverse Section and Section through South Aisle.

Figs. 25, 26, 27.



Constructive Section of the Interior Arrangement and Constructive Section of the Rear

Fig. 28.

Fig. 29.


Sections of Mouldings.

Fig. 30.