Hagia Sophia: A Christian Monument to the Power of Faith

Hagia Sophia during its time as a mosque. Illustration by Gaspare Fossati and Louis Haghe from 1852.

“In his laudatory book on Justinian’s architectural production, the historian Procopius reported that Hagia Sophia had a powerful effect on Christians, serving not only as an important landmark in the city but as a means through which one could know and understand God. He wrote, ‘And whenever one enters the church to pray, one understands immediately that it has been fashioned not by any human power or skill but by the influence of God. And so the mind is lifted up to God and exalted, feeling that He cannot be far away but must love to dwell in this place which He has chosen’” (Kilde 56). In Sacred Power, Sacred Space, Jeanne H. Kilde uses Procopius’ description of Hagia Sophia to illustrate the key ideas of Christian architecture during the Byzantine Age of Spirituality, mainly the purpose of “housing the Lord,” or invoking the presence of the divine in the observer’s mind through architectural marvel. Constructed between 532 and 537 during Justinian I’s reign over the Byzantine Empire, Hagia Sophia has stood tall over Constantinople for nearly a millennium and a half. It has seen many empires come and go throughout its storied existence, the most notable of which is the Ottoman Empire. After the conquest of Constantinople in 1453, Hagia Sophia was transformed into a mosque and became symbolic for Islam as it was for Christianity. However, even with the changes made under Ottoman rule, Hagia Sophia still retains many of its original ideas and design cues. It stands as a paragon of Christian beliefs during the Byzantine Age of Spirituality, a testament to the power of faith.

While the Hagia Sophiastands to this day from the time of its construction, two churches had existed on the same grounds prior to Justinian’s reign. The first church, known as the “Great Church” or “Magna Ecclesia” in Latin, stood during Roman emperor Constantine the Great’s reign. Inaugurated by Constantius II, son of Constantine, Magna Ecclesia fell when it was burned down in 404 during riots (hagiasophia.com). Not long after its destruction, then Emperor Theodosius II had it repaired and restored. It is unknown whether this second church followed the same planning as the first, and regardless, rioters burned the church to the ground during the Nika riots of 532 (hagiasophia.com). Since it was destroyed, historians cannot make a direct and accurate comparison between the old church and Hagia Sophia. However, it is unlikely a coincidence that Hagia Sophia is unique in combining elements of a basilica with those of a centrally planned church. Firstly, the interior layout measures 70 by 76 meters (Sullivan 4). Further, the half-domes that support the central dome extend the nave in length, creating an elliptical area. Alice Isabella Sullivan, an art historian, details the novelty of the design relative to its contemporaries in her article “Hagia Sophia Through the Ages,” stating that: “The engineering feat successfully juxtaposes a longitudinal basilical plan that became characteristic of Western Christian churches, with a centralised one often found in martyria, mausolea, baptisteries, and pilgrimage churches. As such, in its plan, Hagia Sophia was designed with a naos with side aisles, and a semicircular apse facing east, as well as a narthex preceded by an atrium toward the west” (Sullivan 4). In other words, the church was designed with a central temple area in mind, with an external area designated for those not eligible for entry into the general congregation. See Fig. 1 for a comparison between the three designs.

Fig. 1. A comparison between the floor plans of three churches, Old St. Peter’s Basilica, the Church of Santa Constanza, and Hagia Sophia. They are a basilica, a central plan, and a hybrid plan respectively. Note the attributes of both present in Hagia Sophia. (Stokstad).

A critical factor in what makes the engineering of Hagia Sophia so unique lies in the background of its architects, Anthemius of Tralles and Isidorus of Miletus. Neither of them were formally trained in architecture, but they were competent mathematicians whose visions aligned to produce the many innovations found in Hagia Sophia. Procopius noted the significance of their enlistment in Buildings, going as far as to claim that God had provided Emperor Justinian with the exact minds he needed to carry out the construction of the church:

Anthemius of Tralles, the most learned man in the skilled craft which is known as the art of building . . . and associated with him with another master-builder, Isidorus by name, a Milesian by birth, a man who was intelligent and worthy to assist the Emperor Justinian. Indeed this also was an indication of the honour in which God held the Emperor, that He had already provided the men who would be most serviceable to him in the tasks which were waiting to be carried out (11-13).

Procopius’ regard for Anthemius and Isidorus was not unfounded, but his praise of Anthemius as the most learned in building was likely influenced by his observations throughout the construction of the Hagia Sophia. However, they weren’t entirely new to the field. Anthemius was a geometer and studied optics, while Isidorus was a physicist who had studied vaulting, which may have contributed to the intricate vaulting found in the Hagia Sophia(Stokstad 234). It is often stated that their lack of experience as architects afforded them the daringness to carry out plans that trained architects might not have. Furthermore, the techniques used to construct domes and large towers had been refined by the city’s builders (Stokstad 234). Leveraging their knowledge of mathematics to plan the structure in theory, Anthemius and Isidorus worked with architects under their provision, and the Hagia Sophia was completed in five years.

Among all the innovations of Hagia Sophia, the most notable one is the implementation of pendentives to support the dome. Squinches support a typical dome, a system of diagonal lintels that create an octagon to provide a base for a dome to rest upon. In a similar manner, pendentives are concave spherical triangles between arches that curve upward and inward to give a circular base for a dome to rest on, as seen in Fig. 2 (Stokstad 236).

Fig. 2: A comparison between a dome on pendentives and a dome on squinches. The cross-sectional perspective highlights the difference in the shape of the bases that the domes rest on (Stokstad 236).

These pendentives channel the constant forces of the dome into piers or massive columns that can support the weight of a dome. In the eyes of an observer, this form of a dome is remarkable as it appears to be floating, an effect verified by Procopius’ account in Buildings. “The upper part of this structure ends in the fourth part of a sphere (sphaira), and above it another crescent-shaped (mênoeides) structure rises, fitted to the adjoining parts of the building, marvellous in its grace, but by reason of the seeming insecurity of its composition altogether terrifying. For it seems somehow to float in the air on no firm basis, but to be poised aloft to the peril of those inside it. Yet actually it is braced with exceptional firmness and security” (17). Note Procopius’ acknowledgment of the deceptive design. The piers were designed to be hidden such that the visitors inside Hagia Sophia wouldn’t immediately comprehend the nature of the dome, attributing its grandness instead to the divine, in adherence with the artistic goal of “housing the Lord” (Procopius 27).

Anthemius and Isidorus ingeniously used the combination of several techniques to solidify the floating effect of the dome. The dome has forty windows that run along its base, allowing light to shine through. While this may seem counterintuitive for structural integrity, the weight of the dome rested on the piers, and exterior buttressing was added to provide further support. “In fact, when the first dome fell in 558, it did so because a pier and pendentive shifted and because the dome was too shallow and exerted too much outward force at its base, not because the windows weakened the support” (Stokstad 237). Furthermore, the dome was decorated with a gold mosaic, and when the light shone through the windows of the dome, it created a dazzling effect to the human eye. Procopius acknowledged the combination of these effects as bewildering. The intricacy with which the dome was constructed caused one’s gaze to constantly shift between the many details of the structure, unable to decide which one to admire over another (Buildings 23). As such, the overwhelming beauty of the dome left spectators in awe.

The complexity of the layout from the observer’s perspective was an intentional design choice by the engineers of Hagia Sophia to invoke the presence of the divine in visitor’s minds. In making the dome and the altar the focal point of the church, the architects used hybrid planning as the foundation for this complexity. As one walks through the central area of the Hagia Sophia, the massive piers, coupled with the column-laden aisles, ascend into a series of half domes, which support the main dome of the church. At the ground level, the space feels crowded, and the gaze is relieved of this confusion by following the structure to the region in which there is the most space, the dome:

The form of the basilica led the worshipper directly to the sanctuary and the altar where the miracle of the Eucharist occurred, reifying the sacramental relationship between humanity and God, but at the same time the form of the domed church led the eye of the worshipper upward, to the heavens—God’s domain itself” (Kilde 55-56).

By contrasting a visually complex architectural system in the lower levels of Hagia Sophia with the floating and weightless splendor of the dome, Anthemius and Isidorus achieved what remains an artistic spectacle. The summation of the numerous details throughout Hagia Sophia reflects the omnipresent quality of the divine.

Since its completion in 537, Hagia Sophia has undergone several transformations. While the building as it stands today is composed of mostly the original construction, several changes have led to what could be considered a new version aside from Anthemius’ and Isidorus’ vision. The dome has been reconstructed and repaired on multiple occasions. In 557, the original dome collapsed due to an earthquake and was replaced by an even larger dome designed by Isidorus the Younger, the nephew of Isidorus of Miletus (Sullivan 9). The Byzantines repaired the dome in 869, 989, and 1346, and ultimately, Isidorus the Younger’s design is still standing today (Stokstad 237). The most striking adjustments made to Hagia Sophia occurred during Ottoman rule.

With the Ottoman conquest of Constantinople in 1453, the Byzantine Empire fell. Sultan Mehmet II, then ruler of the Ottoman Empire, had declared that Hagia Sophia was repurposed to serve as a mosque, or a house of worship for Muslims. Islamic rules dictate that no images of God or any of his prophets are to be made, and are seen scornfully by the Islamic community. However, in a surprising act of breaking those conventions, Mehmet II allowed several Christian mosaics to remain in acknowledgment of their religious and artistic significance. Unfortunately, to the dismay of preservationists, future sultans who were more conservative had all the mosaics plastered over (Bordewich). Furthermore, four minarets, or towers used for the Muslim call to prayer, were added at each corner of the church on the exterior. Likewise, the interior was also adorned with Islamic art, as “giant circular framed disks inscribed with the names of Allah, Prophet Mohammed, the first four caliphs (Abu Bakr, Umar, Uthman, and Ali), and the two grand-children of Mohammed, Hassan and Hussain, were installed around the naos” (Sullivan 25). Hagia Sophia remained the principal mosque of then Istanbul in 1453 until centuries later, after the dissolution of the Ottoman Empire.

In 1934, Kemal Ataturk, the first president of Turkey, ordered for the Hagia Sophia to be transformed from mosque to museum (Bordewich). In the time afterwards, UNESCO added the building to the list of UNESCO World Heritage sites. Furthermore, due to neglect in maintenance, the Hagia Sophia was listed by the World Monuments Fund (WMF) in their 1996 and 1998 watch lists, who provided a series of restorations in the late 1990s until 2006 to aid in the preservation of many mosaics as well as the dome (World Monuments Fund). While this sounds promising, Turkey’s history of upkeeping the Hagia Sophia has been muddled, with the WMF acknowledging that although their project was complete, other areas would continue to require further work. In a 2008 visit to Hagia Sophia, journalist and writer Fergus Bordewich detailed the level of deterioration he saw:

Huge sections of ceiling are peeling and flaking, stained by water seepage and discolored by age and uneven exposure to light. Acres of stucco must be replaced. Windows must be repaired, new glass installed, warped frames replaced. Hundreds of marble panels, now grime-encrusted, must be cleaned. Irreplaceable mosaics must somehow be restored and protected (Bordewich).

It's clear that the WMF’s brief mention of further conservation required vastly understates the extent to which the Hagia Sophia has declined. After this period of time, the information regarding restoration efforts seems to be unclear.

According to the official website of the Hagia Sophia, the structure received many years of restoration work, with 600 square meters of mosaics and Islamic calligraphy on the walls receiving care. Further work was done by 2012 to renovate ornaments and marble pieces found in the interior, with the page also noting that a complete restoration may be impossible (hagiasophia.com). In a 2021 interview by Anadolu Agency, Istanbul Provincial Director of Culture and Tourism Coşkun Yılmaz stated that “We can say that the repairs have been carried out for 20 years with great care, patience and scientific sensitivity . . . extensive work was carried out, especially in the restoration of the interior and dome of the structure” (Daily Sabah). Yet in spite of this statement, many photos of the Hagia Sophia’s interior after the aforementioned restoration can be seen in the article showing paint peeling away throughout the ceiling, with the once shining golden dome also having lost much of its splendor. The Turkish government’s efforts to maintain the structure are questionable, and it is further alarming when one considers their recent actions in using the Hagia Sophia politically to cater to their large group of Muslim constituents.

In a controversial move in July 2020, Tayyip Erdogan, President of Turkey, had the Hagia Sophia reconverted into a mosque, an action met with negative reactions by UNESCO, the World Council of Churches, and secularists. Turkey’s highest administrative court ruled that Ataturk’s conversion of the Hagia Sophia from mosque to museum was illegal, and claimed the building to be the personal property of Sultan Mehmet II who had ordered the conversion of the Hagia Sophia into a mosque (BBC). This all took place without any dialogue between Turkey and UNESCO, with the latter finding out after Turkey had already made their decision (UNESCO). Since its conversion back to a mosque, Hagia Sophia has been used regularly for Muslim prayer services. By going through with this move, Erdogan has appealed to Turkey’s large Muslim population during a period of economic strife amidst the ongoing pandemic. Here, Erdogan contradicts himself, as just over a decade prior, he was staunchly enforcing law against opening Hagia Sophia to Muslim prayers (Bordewich). While the Turkish government asserts that this change in status will not result in the destruction of the Christian art in the building, this statement is subject to skepticism. Between failure of upkeep, not consulting with UNESCO prior to converting it to a mosque, and Erdogan’s pivot from a secular position, Turkey has solidified that the Hagia Sophia’s future is uncertain.

When Ataturk had the Hagia Sophia converted into a museum, he stated that it was a “monument for all civilization” (Bordewich). Here, many Christians, Muslims, and others alike would argue that the church is theirs to preside over, each based on their previous stewardships over the church. Indeed, these groups have a stake in Hagia Sophia and its storied history. Nevertheless, by orienting their goals around restoring Hagia Sophia as a place of worship for their particular faiths, Christians and Muslims alike overlook that the structure will invoke the presence of the divine independently of any religion. While Turkey cites Mehmet II’s ownership of the Hagia Sophia as basis for converting the structure to a mosque, they fail to acknowledge Mehmet II’s values in preservation. While the sultan had converted Hagia Sophia into a mosque, he preserved Christian mosaics of divine figures despite his own Islamic beliefs, demonstrating the importance of conservation (Bordewich). On the contrary, sultans after Mehmet II and Erdogan are of the same vein, being parties that leverage the grandeur of a historical site to bolster their own power. Even the World Council of Churches, representing more than 500 million Christians, stated that the conversion of the Hagia Sophia to a mosque "will inevitably create uncertainties, suspicions and mistrust, undermining all our efforts to bring people of different faiths together at the table of dialogue and co-operation" (BBC).

Throughout all its iterations, from church, to museum, to mosque, one thing remains clear about the Hagia Sophia. Art is often created such that some degree of interpretation is left to the whims of the observer. In the same vein, wherever the mind cannot fully understand something as complex as Hagia Sophia’s architectural marvel, their minds will often attribute the existence of that marvel to faith. It is more than likely that Anthemius and Isidorus applied this concept to their advantage when they conceived the church’s design. Ultimately, the structure embodies the artistic values of the Byzantine Age of Spirituality, and the Hagia Sophia will continue to invoke the presence of the divine for whoever lays their gaze upon it, but only as long as its stewards do their part in taking care of it. Regardless of the restoration efforts, the Turkish government’s perception of how well the Hagia Sophia is cared for is alarming. In the same vein, it remains unclear as to whether Erdogan will continue in his trend of appealing to Turkey’s large Muslim base, and we may lose precious pieces of culture and history should the mosaics be once again plastered over. As Sullivan states in Hagia Sophia Through the Ages, “the building will continue to awe as it has done for centuries. Hagia Sophia is, ultimately, an expression of human achievement and its responsible stewardship ought to be a collective effort and at the forefront of all concerns” (30).

Works Cited

Anadolu Agency. “Restoration of Istanbul's Hagia Sophia Sets Example for World.” Daily Sabah, 18 Apr. 2021, https://www.dailysabah.com/arts/restoration-of-istanbuls-hagia-sophia-sets-example-for-world/news.

Bordewich, Fergus M. “A Monumental Struggle to Preserve Hagia Sophia.” Smithsonian Magazine, 1 Dec. 2008, https://www.smithsonianmag.com/travel/a-monumental-struggle-to-preserve-hagia-sophia-92038218/.

Hagia Sophia, https://www.hagiasophia.com/.

“Hagia Sophia.” World Monuments Fund, https://www.wmf.org/project/hagia-sophia.

“Hagia Sophia: World Council of Churches Appeals to Turkey on Mosque Decision.” BBC News, 11 July 2020, https://www.bbc.com/news/world-europe-53375739.

Kilde, Jeanne Halgren. Sacred Power, Sacred Space: An Introduction to Christian Architecture. Oxford University Press, 2008.

Procopius, Buildings, Book I (Part 1.20-78).

Stokstad, Marilyn, and Michael W. Cothren. “Chapter 7: Jewish, Early Christian, and Byzantine Art.” Art History, 4th ed., vol. 1, Prentice Hall, 2011, pp. 227–237.

Sullivan, Alice Isabella. “Hagia Sophia Through the Ages.” Phronema, vol. 36, no. 1, 2021, pp. 1–30: Link to document.

“UNESCO Statement on Hagia Sophia, Istanbul.” UNESCO, 13 July 2020, https://en.unesco.org/news/unesco-statement-hagia-sophia-istanbul.