▁the ▁region ▁even ▁after ▁the ▁death ▁of ▁Ch ag ata i . ▁In ▁ 1 2 3 8 ▁there ▁was ▁a ▁Muslim ▁u pr ising ▁in ▁B uk h ara , ▁but ▁Mah m ud ' s ▁son ▁Mas ' ud ▁cr ushed ▁it ▁the ▁next ▁year ▁before ▁Mong ol ▁troops ▁were ▁able ▁to ▁arrive , ▁thereby ▁saving ▁the ▁popul ace ▁from ▁Mong ol ▁ven ge ance . ▁ ▁Ch ag ata i ▁Khan ▁died ▁in ▁ 1 2 4 2 ▁and ▁was ▁succeeded ▁by ▁his ▁grand son ▁Q ara ▁H ü leg ü , ▁whose ▁father ▁Mut uk an ▁had ▁been ▁killed ▁in ▁ 1 2 2 1 ▁during ▁the ▁Sie ge ▁of ▁B am yan . ▁Q ara ▁H ü leg ü ▁was ▁too ▁young ▁to ▁rule ▁independently ▁so ▁the ▁wid owed ▁k hat un ▁E bus k un ▁ruled ▁as ▁reg ent ▁in ▁his ▁place . ▁In ▁ 1 2 4 6 , ▁Gü y ük ▁Khan ▁replaced ▁him ▁with ▁one ▁of ▁his ▁un cles , ▁Yes ü ▁M ö ng ke . ▁ ▁Yes ü ▁M ö ng ke ▁came ▁to ▁power ▁because ▁he ▁was ▁a ▁personal ▁friend ▁of ▁Gü y ük ▁Khan . ▁He ▁was ▁a ▁dr unk ▁who ▁left ▁the ▁affairs ▁of ▁the ▁state ▁to ▁his ▁wife ▁and ▁minister ▁Be ha ▁ad - D in ▁Marg hin ani . ▁In ▁ 1 2 5 2 ▁he ▁was ▁de posed ▁by ▁M ö ng ke ▁Khan , ▁who ▁installed ▁Q ara ▁H ü leg ü ▁again . ▁