From a very early period there was a town on the east back of The Nile , Opposite The Pyramids which bore the name of Khere - Ohe , Or '' Place Of Combat '' . Because Horus and set were believed to have fought once . The greeks called it . Babylon , And the Romans presereved this name when they built up the settement into a stronghold . After The Arab conquest in 641 A.D. The Caliphs built a New Capital in the plain to the north of the Roman stronghold , Naming it Fustat , Or Misr El - Fustal or Qaahira meaning '' One Who Conquers Or Prevails .