▁L anz hou ▁pre fect ure ▁for ▁the ▁first ▁time , ▁retain ing ▁this ▁name ▁under ▁the ▁Tang ▁dynast y ▁( 6 1 8 – 9 0 7 ). ▁In ▁ 7 6 3 ▁the ▁area ▁was ▁over run ▁by ▁the ▁Tib et an ▁Empire ▁and ▁in ▁ 8 4 3 ▁was ▁conquer ed ▁by ▁the ▁Tang . ▁Later ▁it ▁fell ▁into ▁the ▁hands ▁of ▁the ▁Western ▁X ia ▁dynast y ▁( which ▁fl our ished ▁in ▁Q ing hai ▁from ▁the ▁ 1 1 th ▁to ▁ 1 3 th ▁century ) ▁and ▁was ▁subsequently ▁absor bed ▁by ▁the ▁Song ▁dynast y ▁( 9 6 0 – 1 1 2 6 ) ▁in ▁ 1 0 4 1 . ▁The ▁name ▁L anz hou ▁was ▁re est ab lished , ▁and ▁the ▁county ▁renamed ▁L anz hu an . ▁ ▁After ▁ 1 1 2 7 ▁it ▁fell ▁into ▁the ▁hands ▁of ▁the ▁Jin ▁dynast y , ▁and ▁after ▁ 1 2 3 5 ▁it ▁came ▁into ▁the ▁possession ▁of ▁the ▁Mong ol ▁Empire . ▁ ▁Under ▁the ▁M ing ▁dynast y ▁( 1 3 6 8 – 1 6 4 4 ) ▁the ▁pre fect ure ▁was ▁dem oted ▁to ▁a ▁county ▁and ▁placed ▁under ▁the ▁administration ▁of ▁L int ao ▁superior ▁pre fect ure , ▁but ▁in ▁ 1 4 7 7 ▁L anz hou ▁was ▁re est ab lished ▁as ▁a ▁political ▁unit . ▁ ▁The ▁city ▁acquired ▁its ▁current ▁name ▁in ▁ 1 6 5 6 , ▁during