The Former Qin (351-394) was a state of the Sixteen Kingdoms in China. Founded by the Fu family of the Di ethnicity, it completed the unification of North China in 376. Its capital had been Xi'an up to the death of the ruler Fu Jiān. Despite its name, the Former Qin was much later and less powerful than the Qin Dynasty which ruled all of China during the 3rd century BCE. The adjective "former" is used to distinguish it from the "Later Qin" state (384-417).
The defeat of the Former Qin in the Battle of Fei River and the subsequent uprisings split the Former Qin territory into two noncontiguous pieces after the death of Fu Jiān: one located at present day Taiyuan, Shanxi and was soon overwhelmed in 386 by the Xianbei under the Later Yan and the Dingling. The other struggled in its greatly reduced territories around the border of present day Shaanxi and Gansu until disintegration in 394 under years of invasions by the Western Qin and the Later Qin.
In 327, the Gaochang commandery was created by the Former Liang under the Han chinese ruler Zhang Gui. After this, significant Han chinese settlement occurred, a major, large part of the population becoming Chinese. In 383 The General Lu Guang of the Former Qin seized control of the region.
All rulers of the Former Qin proclaimed themselves "Emperor" except for Fu Jiān, who claimed the title "Heavenly Prince" (Tian Wang) but was posthumoustly considered an emperor.
Read more about Former Qin: Rulers of The Former Qin