The third-century Persian monument Taq Kasra (also transcribed as Taq-i Kisra, Taq-e Kesra meaning Iwan of Khosrow) or Arch of Ctesiphon, is the world’s largest brick vault. The archway is considered a landmark in the history of architecture and is the world’s largest single-span baked-brick arch. It is the only visible remaining structure of the ancient city of Ctesiphon. It is located near the modern town of Salman Pak, near Baghdad in Iraq. The town is named after Salman the Persian or Salman al-Farsi. He was a companion of prophet Muhammad and the first Persian who converted to Islam. He translated the Quran into Persian, thus becoming the first person to interpret and translate the Quran into a foreign language.
Ctesiphon, pronounced as Taysafun, is an ancient city located on the bank of Tigris adjacent to the Hellenistic city of Seleucia and about 35 kilometres from the present-day Baghdad. It became the capital of the Parthian Empire (247 BCE-224 CE) in about 58 BCE, and remained the capital of the Sassanid Empire (224-651 CE) until the Muslim conquest of the area in 637 CE.
Ctesiphon began life as a small and unimposing cluster of dwellings across the river from the city of Seleucia-on-the-Tigris, capital of the Hellenistic kings, who at the height of their powers had ruled over a sprawling inheritance stretching from the shores of the Aegean to the Hindu Kush.
Classical writers claimed that Ctesiphon was founded by the Parthian king Vardanes. The first reliable mention of Ctesiphon, however, is as a Greek army camp on the east bank of the Tigris River opposite the Hellenistic city of Seleucia. Since then the course of the river has shifted, no longer flowing between the ruins of the two cities but instead dividing Ctesiphon itself.
Ctesiphon developed into a rich commercial metropolis, merging with the surrounding cities along both shores of the river, including Seleucia. Ctesiphon and its environs are therefore referred to as al-Mada’in (an Arabic word meaning “the two cities”). In the late sixth and early seventh century, it was one of the largest cities in the world.
After a Parthian conquest of the city in 141 BCE, it became an important administrative centre for the Parthian empire. In 129 BCE, when the Parthians annexed Babylonia, they found Ctesiphon a convenient residence and cantonment, and under their rule Seleucia and its royal suburb of Ctesiphon came to form a twin city and a capital of the empire. After a long rebellion in the city lasting seven years from 35 to 42 CE, Ctesiphon became the seat of government and royal residence. Muslim Arabs took over the area in 637 CE, but it continued to remain prominent until the establishment of the Abbasid capital of Baghdad in the middle of the eighth century. Taq Kasra was gradually neglected after the Arab invasion of Persia. Subsequent floods destroyed all remaining structures, including Taq Kasra, one third of which was swept away by a flood in 1888.
After the death of Alexander the Great in 323 BCE in Babylon, Seleucus Nicator founded Seleucia-on-the-Tigris at the end of the fourth century BCE with the aim of attracting the inhabitants of Babylon, despite its initial status as a Greek colony of the Seleucid kingdom. With the foundation of the city of Seleucia as a Greek colony, this region became an arena in which the populations from the East and West came together and created a new more cosmopolitan culture that had not yet been seen in Iraq. This multiculturalism manifested itself in numerous ways as reflected in the artwork and architecture of the region. The most prominent example of the enormous power and prestige held in these cities is the Taq Kasra, a huge vaulted iwan. An iwan is a rectangular hall or space, usually vaulted, walled on three sides, with one end entirely open.
The Taq Kasra is now all that remains above ground of a city that was, for seven centuries, the main capital of the successor dynasties of the Persian empire: Parthians and Sassanids. The structure left today was the main portico of the audience hall of the Sassanids who maintained the same site chosen by the Parthians and for the same reason, namely proximity to the Roman Empire, whose expansionist aims could be better contained at the point of contact.
The exact time of construction of the arch is not known with certainty. Some historians believe the founder is Shapour I who ruled Persia from 242 to 272 CE and some other believe that construction possibly began during the reign of Anushiruwan the Just (Khosrow I) after a campaign against the Byzantines in 540 CE. The arched iwan hall, open on the facade side, was about 37 meters high 26 meters across and 50 meters long, the largest man-made, parabolic barrel vault constructed without centring and spanning. The arch was part of the imperial palace complex. The throne room was presumably under or behind the arch. Its construction at that time must have been a miracle of architectural planning. A descendant of ancient Mesopotamian structures in style, it embodied a skilful development of temples and palaces of the 3rd millennium BCE, when the front part of great buildings would consist of large halls topped by high arches — as seen clearly at the entrances of Assyrian cities.
Before the US-led invasion of 2003, the area had gardens, as well as a popular museum. But now there is little foliage because the irrigation pipes were destroyed and the trees were cut down for firewood, while the museum was looted after Saddam’s overthrow.
In the recent years the Iraqi Ministry of Culture has invited a Czech firm to restore the site. Various objects have been discovered around Taq Kasra-Ctesiphon area, mostly in the late 1920s and early 1930s. The artefacts are now mostly kept at the State Museum of Berlin (Pergamonmuseum) and Metropolitan Art Museum in New York.