▁family ▁ ▁Last ▁phase ▁of ▁con quest ▁ ▁A ▁veter an ▁military ▁commander , ▁Ah na f ▁ibn ▁Q ais , ▁was ▁appointed ▁by ▁U mar ▁for ▁the ▁con quest ▁of ▁Kh uras an , ▁which ▁in ▁those ▁time ▁compr ises ▁most ▁of ▁present - day ▁north ▁eastern ▁Iran , ▁Afghan istan ▁and ▁Turk men istan . ▁On ▁hearing ▁of ▁the ▁Muslim ▁advance , ▁Y az de ger d ▁III ▁left ▁for ▁B alk h . ▁No ▁resistance ▁was ▁offered ▁at ▁Mer v , ▁and ▁the ▁Muslim s ▁occupied ▁the ▁capital ▁of ▁Kh uras an ▁without ▁a ▁fight . ▁after ▁that , ▁for ▁sometimes ▁after ▁U mar ' s ▁death ▁Ah na f ▁was ▁re - app oint ed ▁again ▁by ▁Abd ul lah ▁I bn ▁A am ir ▁for ▁pac ifying ▁many ▁revol ting ▁areas ▁including ▁Qu z est an ▁and ▁Her at . ▁ ▁Re con quest ▁ ▁in ▁ 6 5 4 ▁the ▁Battle ▁of ▁Bad gh is ▁occurred ▁between ▁the ▁Kar en ▁family ▁and ▁their ▁He ph th al ite ▁al lies ▁against ▁the ▁R ash id un ▁C ali ph ate ▁led ▁by ▁Abd ul lah ▁ibn ▁A am ir . ▁this ▁battle ▁was ▁completed ▁the ▁first ▁phase ▁of ▁R ash id un ▁Con quest ▁in ▁the ▁soil ▁of ▁Iran . ▁Despite ▁initial ▁Arab ▁set back s ▁and ▁the ▁T urg esh ▁invasion ▁of ▁Kh uras an , ▁As ad ▁succeeded ▁in ▁inf lic ting ▁a ▁defeat ▁upon ▁the ▁k h agan ▁in ▁person ▁in ▁the ▁Battle ▁of