 An alternative theory is that the mosque 's name is derived from the names given by the Fatimid caliphs to their palaces . Those near the mosque were collectively named al @-@ Qusur al @-@ Zahira ( االقصور الزاهرة , " the Brilliant Palaces " ) by al @-@ Aziz Billah , and the royal gardens were named after another derivative of the word zahra . The palaces had been completed and named prior to the mosque changing its name from Jāmi ' al @-@ Qāhira to al @-@ Azhar . 
