▁J inch eng ▁command ery ▁( j ù n ), ▁and ▁later ▁of ▁the ▁J inch eng ▁county ▁( xi àn ), ▁later ▁renamed ▁Y un w u . ▁The ▁city ▁used ▁to ▁be ▁called ▁the ▁Golden ▁City , ▁and ▁since ▁at ▁least ▁the ▁first ▁mill en ni um ▁BC ▁it ▁was ▁a ▁major ▁link ▁on ▁the ▁ancient ▁Northern ▁Sil k ▁Road , ▁ ▁and ▁also ▁an ▁important ▁historic ▁Y ellow ▁River ▁crossing ▁site . ▁To ▁protect ▁the ▁city , ▁the ▁Great ▁Wall ▁of ▁China ▁was ▁extended ▁as ▁far ▁as ▁Y umen . ▁Part s ▁of ▁the ▁Great ▁Wall ▁still ▁exist ▁within ▁the ▁built - up ▁area . ▁ ▁After ▁the ▁fall ▁of ▁the ▁Han ▁dynast y , ▁L anz hou ▁became ▁the ▁capital ▁of ▁a ▁succession ▁of ▁trib al ▁states . ▁In ▁the ▁ 4 th ▁century ▁it ▁was ▁briefly ▁the ▁capital ▁of ▁the ▁independent ▁state ▁of ▁Li ang . ▁The ▁Northern ▁Wei ▁dynast y ▁( 3 8 6 – 5 3 4 ) ▁re est ab lished ▁J inch eng ▁command ery , ▁ren aming ▁the ▁county ▁J inch eng ▁( 金 城 ▁' G old ▁city '). ▁M ixed ▁with ▁different ▁cultural ▁her it ages , ▁the ▁area ▁at ▁present - day ▁G ans u ▁province , ▁from ▁the ▁ 5 th ▁to ▁the ▁ 1 1 th ▁century , ▁became ▁a ▁center ▁for ▁Buddh ist ▁study . ▁Under ▁the ▁S ui ▁D ynast y ▁( 5 8 1 – 6 1 8 ) ▁the ▁city ▁became ▁the ▁seat ▁of