contact. The structure was captured by the Arabs during the conquest of Persia in AD 637. They then used it as a mosque for a while until the area was gradually abandoned. In the early 10th century, the Abbasid caliph al-Muktafi dug up the ruins of the palace to reuse its bricks in the construction of the Taj Palace in Baghdad. The monument is also the subject of a poem by Khaqani, who visited the ruins in the 12th century. Modern era In 1851, French artist Eugène Flandin visited and studied the structure with Pascal Coste 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, 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 monument was in the process of being rebuilt by Saddam Hussein's government in the course of the 1980s, when the fallen northern wing was partially rebuilt. All works, however, stopped after the 1991 Persian Gulf War. From 2004 to 2008 the Iraqi government cooperated with the University of Chicago's Diyala Project to restore the site at a cost of $100,000.