 Al @-@ Mu 'tasim continued the patronage of scientists and translators , and Baghdad remained a major centre of learning throughout his reign . Among the notable scholars active during his reign were the astronomers Habash al @-@ Hasib al @-@ Marwazi and Ahmad al @-@ Farghani , the polymath al @-@ Jahiz , and the distinguished Arab mathematician and philosopher al @-@ Kindi , who dedicated his work On First Philosophy to his patron al @-@ Mu 'tasim . 
