Youssef Nabil, Mohamed, Cairo, 2001 (Courtesy H.P. Horst, Galerie Volker Diehl, Berlin) Gelatin Silver Print, hand coloured, 39x27cm. www.galerievolkerdiehl.com

David Roberts, A Modern Mansion, Cairo, Roberts’ travels to the Middle East from 1838-1839 were described by his biographer James Ballantine as the “great central episode of his artistic life”. He returned from this trip laden with material which, over...