▁Nas r ▁ibn ▁Say yar . ▁In ▁July ▁ 7 3 8 , ▁at ▁the ▁age ▁of ▁ 7 4 , ▁Nas r ▁was ▁appointed ▁as ▁governor ▁of ▁Kh uras an . ▁Despite ▁his ▁age , ▁he ▁was ▁widely ▁respect ed ▁both ▁for ▁his ▁military ▁record , ▁his ▁knowledge ▁of ▁the ▁affairs ▁of ▁Kh uras an ▁and ▁his ▁ab ilities ▁as ▁a ▁states man . ▁Julius ▁Well hausen ▁wrote ▁of ▁him ▁that ▁" H is ▁age ▁did ▁not ▁affect ▁the ▁fresh ness ▁of ▁his ▁mind , ▁as ▁is ▁test ified ▁not ▁only ▁by ▁his ▁de eds , ▁but ▁also ▁by ▁the ▁vers es ▁in ▁which ▁he ▁gave ▁expression ▁to ▁his ▁feelings ▁till ▁the ▁very ▁end ▁of ▁his ▁life ". ▁However , ▁in ▁the ▁climate ▁of ▁the ▁times , ▁his ▁nom ination ▁ow ed ▁more ▁to ▁his ▁appropriate ▁trib al ▁affili ation ▁than ▁his ▁personal ▁qual ities . ▁the ▁problems ▁of ▁Trans ox iana ▁could ▁be ▁resolved ▁although ▁the ▁Um ay y ad ▁was ▁on ▁decl ine ▁and ▁being ▁replaced ▁by ▁the ▁Abb as id ▁ ▁During ▁Abb as id ▁era ▁ ▁The ▁w ides p read ▁dis content ▁with ▁late ▁Um ay y ad ▁was ▁explo ited ▁by ▁Ab u ▁Muslim , ▁who ▁operated ▁in ▁the ▁eastern ▁province ▁of ▁Kh uras an . ▁This ▁province ▁was ▁part ▁of ▁Iran ian ▁world ▁that ▁had ▁been ▁heavily ▁colon ised ▁by ▁Arab ▁tribes ▁following ▁the ▁Muslim ▁con quest ▁with ▁the ▁intent ▁of ▁replacing ▁Um ay y ad ▁dynast y ▁which ▁is ▁proved ▁to ▁be ▁successful ▁under