Yao Chang had been had been a powerful general and Qiang chieftain under the Later Zhao emperor Shi Hu, but after Later Zhao's collapse after Shi Hu's death, Yao Chang's older brother Yao Xiang had attempted to start an independent state but was defeated and killed by Former Qin forces.
Yao Chang became a Former Qin general, but after an incident in 384 after the Former Qin emperor Fu Jiān's defeat at the Battle of Fei River, Yao Chang feared that Fu Jiān would kill him and therefore rebelled.
He subsequently captured and killed Fu Jiān, who had saved his life when Yao Xiang was defeated, causing many historians to view him as a traitor and murderer.
Western Yan forces, under its emperor Murong Chong, had then occupied Chang'an, and Western Yan and Later Qin had battled on-and-off.
However, the Western Yan people were unhappy that Murong Chong was not leading them back to their homeland in the east, and, in 386, Murong Chong had been assassinated in a coup and replaced with Deng Sui, who was then assassinated and replaced with Murong Yi, under whom the Western Yan people abandoned Chang'an and headed east.
Briefly, Chang'an was held by the Xiongnu chief Hao Nu, but Yao Chang then advanced on Chang'an, and Hao surrendered.
Yao Chang had made Chang'an his capital and claimed the title of emperor of Later Qin.
He had created his wife Lady She as empress and his son Yao Xing as crown prince.
For the next few years, Yao Chang has not been able to attain complete control over the region, as many Di, Qiang, Xiongnu, and Han generals remain semi-independent throughout the region.
Further, in 386, a distant member of Former Qin's imperial Fu clan, Fu Deng, had risen in modern eastern Gansu to oppose him, and after the death of Fu Jiān's son Fu Pi that year, had claimed imperial title and became the main adversary for Yao Chang.
Fu Deng has used Yao Chang's killing of Fu Jiān to good propaganda effect, and for several years has been quite successful in battles against Yao Chang, although the battles have generally been inconclusive in their impact, with neither Fu Deng nor Yao Chang being able to decisively defeat the other.
However, Yao Chang has been able to gradually subdue the other Former Qin generals of the region, taking advantage of Fu Deng's cautiousness.
In 387, for example, after the Former Qin general Fu Zuan had been killed by his brother Fu Shinu, Yao Chang had taken the opportunity to quickly advance against Fu Shinu and defeat him, seizing his troops.
He also, at the same time, seized the remaining cities held by Western Yan west of the Yellow River.
In 389, after losing several battles to Former Qin, Yao Chang becomes apprehensive and thinks that it is Fu Jiān's spirit aiding Former Qin, so he, following Fu Deng's lead, makes an image of Fu Jiān and worships it, claiming to it that he had killed Fu Jiān only to avenge Yao Xiang and asking for forgiveness.
The image does not help Yao Chang, and he eventually cuts off its head and sends it to Fu Deng.
Later that year, as Fu Deng is pressuring Yao Chang, however, Yao Chang makes a surprise attack at night, around Fu Deng's army, against Fu Deng’s logistics base.
Dajie (in modern Xianyang, Shaanxi), capturing it and Fu Deng's wife Empress Mao and killing his sons Fu Bian and Fu Shang.
He initially wants to make Empress Mao his concubine, but after she curses him, he executes her.
While Former Qin and Later Qin will continue to stalemate for the next few years, Fu Deng will be unable to again threaten Later Qin's existence from this point on.
