The exact time of the structure's construction is not known with certainty. Some historians believe it was constructed under
Shapur I who ruled Sasanian Persia from 242 to 272 AD while others believe that construction possibly began during the reign of
Khosrow I after a
campaign against the Byzantines in 540 AD. 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, free standing vault constructed until modern times. The arch was part of the imperial palace complex. The
throne room—presumably under or behind the arch—was more than 30 m (110 ft) high and covered an area 24 m (80 ft) wide by 48 m (160 ft) long. The top of the arch is about 1 meter thick while the walls at the base are up to 7 meters thick. The Arabic poet
Al-Buhturi wrote a famous poem about the ruins in the 9th century. The monument is also the subject of a poem by the Persian poet
Khaqani, who visited the ruins in the 12th century. who remarked "the Romans had nothing similar or of the type." In 1888, a serious flood demolished the greater part of the edifice. In 1940, the British writer
Roald Dahl, then undergoing pilot training at
RAF Habbaniya near
Baghdad took an award-winning photograph using a
Zeiss camera of the Arch of Ctesiphon in Iraq which was subsequently auctioned by the Dahl family to raise funds for the
Roald Dahl Museum and Story Centre. The photo made £6,000. In his autobiography
Boy he writes: : You may not believe it, but when I was eighteen I used to win prizes and medals from the Royal Photographic Society in London, and from other places like the Photographic Society of Holland. I even got a lovely big bronze medal from the Egyptian Photographic Society in Cairo, and I still have the photograph that won it. It is a picture of one of the so-called Seven Wonders of the World, the Arch of Ctesiphon in Iraq. This is the largest unsupported arch on earth and I took the photograph while I was training out there for the RAF in 1940. I was flying over the desert solo in an old Hawker Hart biplane and I had my camera round my neck. When I spotted the huge arch standing alone in a sea of sand, I dropped one wing and hung in my straps and let go of the stick while I took aim and clicked the shutter. It came out fine. The Ministry of Culture also invited a Czech company, Avers, to restore the site. This restoration was completed in 2017. On 7 March 2019, a partial collapse further damaged the Taq Kasra, just two years after its latest restoration was completed. ==Documentary film==