The Cathedral of Hagia Sophia (Greek: Holy Wisdom), the patriarchal Orthodox temple in Constantinople (now Istanbul), was turned into a mosque after being captured by the Ottomans. Now, it is a museum and a world-famous monument of Byzantine architecture.
Scientists William Emerson and Robert L. Van Nuys studied in detail the most spectacular part of the building, its dome, which had originally been spherical and had a diameter of 31 meters. It also stood 51 meters above the floor.
The dome rests on four pillars (sails). Some of its deviations from an ideal sphere or circle were caused by numerous earthquakes and restorations.
In their series of publications from the 1940−50s, Emerson and L. Van Nuys presented a detailed report on the construction of the second dome of St. Sophia by Isidore Jr. and the reconstruction works of the 10th and 14th centuries.
The authors also appreciated the contribution of the architect Trdat from Armenia to the restoration of the cathedral in the 10th century, as testified by Byzantine written sources and the structure’s design.
The scientists concluded that Trdat rebuilt the western part of the dome and strengthened the western arch. After examining the masonry on the inner base of the dome, they determined that its apparent asymmetry is the result of the expansion of the large western arch.
Scientists are convinced that Trdat increased the height of the concave arch and suggested that it was created intentionally due to the dangerous external bulge of the southern part of the dome that appeared in the 6th century.
For a greater stability of the dome, Trdat laid two pairs of windows at the ends of the segment (“Architect Trdat and the dome of Hagia Sophia”, Christina Maranchi).
In 330, Emperor Constantine transferred the capital of the Roman Empire to the city of Byzantium, renaming it New Rome. However, the name didn’t settle down, and the city soon began to be called “Constantinople” instead.
In the same year, Constantine initiated the construction of a basilica that he named Hagia Sophia.
Because of several riots in the city throughout the following centuries, the cathedral has been rebuilt more than once.
During the rebellion of 532, it was simply burned down. Emperor Justinian was ready to flee the country when commander Belisarius and his troops entered Constantinople and suppressed the uprising.
In honor of this victory, Justinian decided to build the largest temple in the world. For this purpose, he bought the land around the burnt basilica and invited famous architects Anthemius from Tralles and Isidore from Miletus.
10.000 workers worked daily at the construction site. The best marble was brought for the cathedral from around the Empire. The workers even brought ready-made columns from the pagan temples of Rome, Athens, Ephesus, and Baalbek.
Many innovations were used during the construction. Lime was prepared on barley water, cement was mixed with oil, and melted gold was complemented by onyxes, topazes, pearls, amethysts, sapphires, and rubies to decorate the throne.
All the income of the Empire went to the construction of the temple. The temple was decorated with mosaics on the golden floor and walls instead of the regular iconostasis. There also were 12 silver columns with golden capitals crowned with icons. The sacristy alone had 40.000 pounds of silver in it.
The temple was completed in five years in 537. Its consecration was accompanied by festivities: the city exulted for fifteen days.
6th-century Byzantine chronicler Procopius wrote about the cathedral:
“…The temple represented a wonderful sight. For those who looked at it, it seemed exceptional, for those who heard about it — absolutely incredible.
It rises up into the height as if directly into the sky. Like a ship on the high waves of the sea, it stands out among other buildings as if leaning over the rest of the city, decorating it as a part of it.
It itself is decorated by the city since, being a part of it and being included into its composition, it as if bends down onto the city that is visible like it is right in your palm…
One could say that the place is not illuminated from the outside by the sun: rather, its shine is born within. So much light spreads in this temple.”
An earthquake in 558 destroyed the eastern part of the dome of Hagia Sophia. Isidore, the nephew of architect Isidore from Miletus, restored and raised the dome by 9 meters. According to witness accounts, Hagia Sophia lost the lightness that used to be admired by the contemporaries so much.
An even stronger earthquake in 989 destroyed the western part of the dome. This time, the restoration of the dome was entrusted to architect Trdat from Armenia.
There are two versions why the restoration of the dome was entrusted to Trdat. According to one version, Trdat at the time was in Constantinople and offered his services. The other version states that Trdat, an architect known in Armenia and the Byzantine Empire, was invited to Constantinople as he had extensive experience with large domes.
Trdat (950−1020) was a famous architect in Bagratid Armenia. After King Ashot III transferred the capital of Armenia from Kars to the city of Ani (now in Turkey near the border with Armenia), Trdat built a domed cathedral in Argina that would serve as the Catholicosate of the Armenian Church.
He also built a basilica cathedral in Ani, the Surb Nshan (Holy Sign) Church in the Haghpat Monastery, as well as the 3-floor Church of St. Gregory in Ani. His architectural works all had large, pronounced domes.
Trdat was an experienced architect. However, Hagia Sophia was a challenge for him: Armenian architects were used to working with large stone blocks, while the dome of Hagia Sophia was built of brick and limestone.
Trdat presented a plan for the restoration of the cathedral, including a draft and a model of the cathedral after the restoration. This was a new thing for the Byzantines since their architects didn’t practice drawing any drafts. In addition, Trdat used sails when building the domes in his projects.
The scale of Constantinople was different, which greatly increased the complexity of the tasks faced by the architect. Trdat improved his methods over the course of the work, which increased the cost of the restoration.
A Byzantine chronicler notes that the falsework erected by Trdat during the restoration of the dome cost the state treasury a thousand livres in gold.
In 994, the restoration of Hagia Sophia was completed. The result of the work of Trdat – now the Aya Sofya Museum – has since been pleasing its visitors for over a thousand years.
Gagkashen church (with English subtitles)