 The city of Cairo was established by Gawhar al @-@ <unk> , a Fatimid general of Greek extraction from Sicily . He originally named it al @-@ Mansuriyya ( <unk> ) after the prior seat of the Fatimid caliphate , al @-@ Mansuriya in modern Tunisia . The mosque , first used in 972 , may have initially been named Jāmi ' al @-@ Mansuriyya ( جامع <unk> , " the mosque of Mansuriyya " ) , as was common practice at the time . It was the Caliph al @-@ Mu ’ izz li @-@ Dīn Allāh who renamed the city al @-@ Qāhira ( <unk> , " Cairo " , meaning , " the Victorious " ) . The name of the mosque thus became Jāmi ' al @-@ Qāhira ( جامع <unk> , " the mosque of Cairo " ) , the first transcribed in Arabic sources . 
