When Chang'an fell to Western Yan forces in 385, they fled to the semi-independent state Chouchi, and after Lü Guang established Later Liang after returning from his Xiyu mission and seizing Liang Province (涼州, modern central and western Gansu), they arrived in his capital Guzang (姑臧, in modern Wuwei, Gansu) in 389.
When Chang'an fell to Western Yan forces in 385, the fleeing population sought refuge in Chouchi, a semi-independent state.  Following Lü Guang's return from his Xiyu mission and subsequent seizure of Liang Province (涼州), they arrived at Guzang (姑臧) in modern Wuwei, Gansu, in 389.