aff ari ▁was ▁defeated ▁at ▁the ▁battle ▁of ▁B alk h ▁by ▁the ▁Pers ian ▁Sam an ids , ▁which ▁reduced ▁the ▁S aff ar id ▁dynast y ▁to ▁a ▁minor ▁trib ut ary ▁in ▁S istan . ▁ ▁In ▁ 1 0 0 2 , ▁after ▁inher iting ▁his ▁father ' s ▁army ▁and ▁territory , ▁Mah m ud ▁of ▁Gh az ni ▁inv aded ▁S istan , ▁d eth ron ed ▁K hal af ▁I ▁and ▁finally ▁ended ▁the ▁S aff ar id ▁dynast y , ▁thus ▁forming ▁his ▁own ▁su zer ain ▁emp ire , ▁the ▁Gh az nav id ▁Empire ▁thus ▁mark ing ▁the ▁extension ▁of ▁Muslim ▁con quest s ▁to ▁the ▁land ▁of ▁Afghan istan ▁and ▁India ▁through ▁his ▁hand . ▁establish ing ▁the ▁second ▁path ▁of ▁Muslim ▁con quest ▁to ▁the ▁far ▁east ▁after ▁the ▁con quest ▁by ▁Muhammad ▁ibn ▁Q as im ▁on ▁Sid h ▁many ▁dec ades ▁earlier ▁during ▁the ▁rule ▁of ▁Um ay y ad . ▁ ▁D ias por a ▁ ▁After ▁the ▁con quest , ▁it ▁is ▁recorded ▁that ▁a ▁massive ▁migration ▁of ▁ 5 0 , 0 0 0 ▁Arab ▁families ▁from ▁Bas ra ▁to ▁Kh uras an . ▁The ▁region ▁was ▁considered ▁the ▁' Second ▁Arab ia ' ▁or ▁' Col ony ▁of ▁Bas ra '. ▁ ▁For ▁Chinese ▁captured ▁at ▁Tal as , ▁Du ▁H uan , ▁was ▁brought ▁to ▁Bag hd ad ▁and ▁tou red ▁the ▁cal i ph ate . ▁He ▁observed ▁that ▁in ▁Mer v ,