Hagia Sophia (Istanbul)

Hagia Sophia exterior

Fig. 1. Exterior of Hagia Sophia complex (Source: Hagia Sophia Research Team)

Hagia Sophia, or “Holy Wisdom,” is one of the world’s most innovative architectural marvels. The building, located in present-day Istanbul, Turkey, embodies a complex history of conversion, both within its walls and through its larger socio-political contexts. It takes on a multiplicity of cultural and religious identities, and despite being constructed thousands of years ago, its position is still not fixed. Recent events regarding its shift from a museum back to a practicing mosque has been the center of controversy and international attention, as well as proven the continuous, living nature of buildings and cultural monuments.

Initially, Hagia Sophia was built as Constantinople’s central cathedral in the 4th century under emperor Constantius II, although its wooden roof led to it burning down. The church was reconstructed in the 5th century under Theodosius II, and this version’s wooden frame, too, led to its fiery demise. In 537 CE, the Byzantine emperor Justinian I rebuilt Hagia Sophia, and this structure stood the test of time and is the building that we know it as today. He felt it crucial to empower himself and his empire through the construction of Hagia Sophia and the city of Constnatinople as a whole. While it has structurally remained very similar to this 6th century version, it has also undergone multiple restorations and been subject to a changing of rulers, resulting in a variety of adaptations and subtracted or added elements. Constantinople was the imperial city of the Byzantine Empire and home of the Eastern Orthodox Church. During the Fourth Crusade in 1204, Constantinople was captured, and Hagia Sophia was converted to a Catholic church, although by 1261 it had been reinstated as an Orthodox church.

The real fall of Constantinople occurred nearly 200 years later in 1453 with the arrival of the Ottoman sultan Mehmet II and the official demise of the Byzantine Empire. Mehmet II conquered the city, made Constantinople the new capital of the Ottoman Empire, and converted Hagia Sophia into a mosque. Instead of entirely destroying the building, as conquerors might typically do to assert their dominance, Mehmet II chose to keep the structural integrity of Hagia Sophia intact, essentially only adding fundamental Islamic elements that would solidify its role as a mosque. Mehmet II must have recognized the architectural innovation of the building and its value as an artistic feat.

Conversion, still, is itself a political statement. In 1935, Kemal Ataturk, the founding father of the modern Republic of Turkey, elected to change Hagia Sophia from its role as an imperial mosque into a secular museum. For years it remained this way, until July of 2020 when the current president of Turkey, Recep Tayyip Erdoğan, decided to convert Hagia Sophia back into a mosque. This decision has been under fire from the international community and is seen as a loss of universal cultural heritage. Hagia Sophia has been subject to an always shifting religious, political, and cultural identity, and its recent conversion has proven that this identity is still in flux today.

Hagia Sophia has been universally revered as an artistic and engineering marvel since its inception. The minds behind its design were engineer Isidore of Miletus and mathematician Anthemius of Tralles. The most striking and unique part of Hagia Sophia’s structural design is its dome, which gives off the impression that it is floating. One of the architectural challenges in constructing the church was connecting a dome, a shape with a round base, onto a structure with a square base. Isidore of Miletus and Anthemius of Tralles solved this problem by employing the pendentive, a rounded, triangular-shaped support that smoothly connects the drum of a dome to a columnar base. This innovation suspends the dome, overcoming the need for heavy supports that interfere with the rhythm and open space of the interior. Given Hagia Sophia’s massive scale, accomplishing this was a monumental feat of its own —although the dome is imperfect in shape due to spreading, the fact that it has stood the test of time speaks to the engineering prowess of the original architects.

View of Hagia Sophia's dome from below

Fig. 2. Hagia Sophia's dome and pendentives from below. (Source: Hagia Sophia Research Team)

The employment of the dome has allowed for the incredibly light and airy interior of Hagia Sophia, as it is pierced at its base with many windows that allow for light to pour into the space from all directions, illuminating the gold mosaic decoration covering the ceilings and walls. Ekphraseis from visitors of Hagia Sophia in its peak condition, prior to the accumulation of dirt or weathering of age, have repeatedly noted its abundant radiance. Its longitudinal axis deviates from the traditional east-west orientation of Orthodox churches and is actually positioned in a line 33.5 degrees south of east. This decision allows for Hagia Sophia to have maximum light exposure, even on the shortest day of the year, and has been advantageous in illuminating the interior.

Upon its initial building, Hagia Sophia featured no figural mosaics, as this period in time corresponded with Iconoclasm. After its passing, however, there was a resurgence in the importance of images in Christianity, and succeeding Byzantine emperors have had religious scenes included in the ceilings, arches, and walls of the church. In the apse, the focus of the building, there is an image of the virgin Mary known as the Theotokos Mosaic. Her position in the apse, which is situated right above a glowing row of windows, allows the viewer to understand she is the mediator for worship of her son, who sits on her lap. The gold surrounding her is illuminated, further emphasizing the connection of light as corresponding with divinity. Other mosaics depict portraits of emperors and their submission to Mary and Christ. Within each of the dome’s pendentives are also seraphim mosaics, which had been plastered over at some point during the Ottoman rule and were uncovered by the Swiss Fossati brothers during restoration in the 1840s.

Theotokos in the Apse

Fig. 3. Theotokos in the Apse (Source: Hagia Sophia Research Team)

The decorative program of Hagia Sophia is also embedded within its structural supports—its floor, walls, and several of its columns are made from unique porphyry and polychrome marble. The origins of these materials are thought to be from specific Mediterranean quarries that had actually ceased their operations by the time of the building’s construction. This history has led scholars to believe that many of its Hagia Sophia’s elements are spoliated from distant places and other buildings, as well as their oft imperfect proportions from one another.

When Mehmet the II initially conquered Constantinople in the 15th century, he chose to refashion the church into a mosque instead of destroying it outright, despite brutally ransacking the city as a whole. As previously mentioned, conversion itself is a subversive tool used to assert dominance. Mehmet used conversion to usurp power from both the Byzantine and Christian empires and while declaring the preeminence of his own religion and imperial power. Under centuries of Ottoman rule, additional Islamic elements like Arabic scriptures, minarets, and a prayer niche were added to Hagia Sophia. Figural representations are traditionally excluded from the Islamic visual language for reasons that parallel Iconoclasm; only God should possess the divine ability to conjure a perfect human form. Despite this custom, detailed drawings made of Hagia Sophia during its phase as a Muslim space of worship have shown that practically none of the Christian religious imagery was covered during a majority of Ottoman reign. This phenomenon has been considered the result of the link between important figures who play significant roles in both the Bible and the Quran.

Since 1935, Hagia Sophia has been a secular museum that became Turkey’s most popular attraction. This decision was controversial in Turkey; members of the Turkish Republic considered this move empowering by opening themselves up to the world, while in contrast, conservatives and nationalists found this choice a form of surrender to the west and a stripping of Muslim identity. Time has shown that Hagia Sophia’s conversion to a museum has been an asset to Turkey, as well as to universal cultural heritage and global education.

President Erdoğan’s 2020 decision to convert Hagia Sophia back into a mosque has marked a new era of controversy surrounding the building. Some have viewed this move as a kind of bluff or a performance of power, particularly in light of Erdoğan’s unpopularity. His tenure has not been well-received by much of the country, and the conversion decree has been considered a public concession to his nationalist base in exchange for continued support. UNESCO has explicitly expressed its disapproval of the decision, especially due to the fact that Erdoğan enacted it without consulting their leadership. President Erdoğan has stated his commitment to keep the building open to the public when not in prayer, in addition to only covering the interior Christian imagery when in session and drawing the curtains back otherwise. Perhaps this seems a compromise to President Erdoğan, but the choice of conversion itself as merely a political tool is a reflection of his insecurity and lack of power as a leader. For hundreds of years of Ottoman rule, these mosaics had been uncovered and untouched—how might Erdoğan defend his decision to change the interior space, despite his arguably more powerful predecessors opting not to? 

erdogan at prayer in hagia sophia

Fig. 4. President Erdoğan leading prayer in Hagia Sophia for the first time in 86 years. (Source: The Guardian)

Hagia Sophia has experienced a plethora of cultural exchange and a variety of political and religious turnovers. Its history is unique and fascinating, and its role as a museum has been integral in elucidating its splendor—as an engineering marvel, an artefact, and a narrator of religion. In this way, we can view Hagia Sophia as a universally significant object whose history does not exclusively belong to Istanbul, but instead is a symbol of global dialogue. Its transformation might play a role in silencing this conversation. The controversy surrounding Hagia Sophia’s conversion reminds us of the living presence of cultural monuments, and why it is urgent that we continue to preserve and protect them.

  • full view Hagia Sophia

    Full view of the Hagia Sophia (Source: Dick Osseman)

  • Virgin detail

    Virgin and Child Mosaic (Source: Dick Osseman)

  • View of apse (Source: Dick Osseman)

  • Deesis Mosaic

    Deësis Mosaic (Source: Dick Osseman)

  • Calligraphic Roundrels (Source: Dick Osseman)

  • Detail of seraphim within pendentive (Source: Dick Osseman)

  • Empress Zoe mosaic

    Empress Zoe Mosaic (Source: Dick Osseman)

  • Mosaic of Leo VI (Source: Dick Osseman)

  • Rubbing of Leo VI from the Mosaic of Leo VI (Source: Harvard Art Museums)

  • Vestibule Mosaic (Source: Dick Osseman)

  • Rubbing of Vestibule Mosaic (Source: Harvard Art Museums)

  • Porphyry columns

    Porphyry Columns (Source: Hagia Sophia Research Team)