Founded in the wake of the Later Zhao dynasty's collapse in 351, it completed the unification of northern China in 376 during the reign of Fu Jiān (Emperor Xuanzhao), being the only state of the Sixteen Kingdoms to achieve so.

All rulers of Former Qin proclaimed themselves "Emperor", except for Fu Jiān who only claimed the title "Heavenly King" (Tian Wang).

The Fu clan of Lüeyang Commandery were originally had the surname Pu (蒲) and claimed descent from the legendary Youhu tribe (有扈) that once dwelled near Chang'an during the Xia dynasty according to records.

During the fall of Western Jin, many refugees fled to join them, prompting their chieftain, Pu Hong to declare independence by proclaiming himself the Duke of Lüeyang.

When Shi Hu seized power in 333, Pu Hong convinced him to resettle the various Di and Qiang tribes in Guanzhong to live around the capital region in Xiangguo.

In accordance to a prophecy, he changed his family name to Fu (苻) and, after briefly being a vassal to the Eastern Jin dynasty, proclaimed himself King of the Three Qins.

Traditional historians describe Fu Sheng as a violent ruler, killing many of his high-ranking officials over trivial matters.

Although a Di, he had a strong background in Confucian education and employed many Han Chinese officials, the most prominent being his Prime Minister, Wang Meng.

With the help of Wang Meng, Fu Jiān shifted the state's initial dependence on mercantile towards agrarian policies by promoting agriculture, building irrigation facilities along with resettling the Xiongnu and Xianbei people to work on the farmlands.

However, Fu Jiān did not listen, and to address Wang Meng's latter concern, he relocated many of the Qiang and Xianbei people to live near the capital while moving the Di to newly-controlled territories, hoping to integrate the various ethnic groups.

In 383, aiming to unify China and despite opposition from most of his ministers, Fu Jiān invaded Jin with a massive army, with records claiming to be at 1 million strong.

Fu Jiān attempted to quell the uprisings, but soon, his Qiang general, Yao Chang also rebelled north of the Wei River, founding the Later Qin dynasty.

Throughout his reign, Fu Deng fought with the Later Qin, finding much success early on before suffering a significant defeat at the Battle of Dajie in 389.

In 394, taking advantage of Yao Chang's death, he carried out one last attack on Later Qin at the Battle of Feiqiao, where his main forces were destroyed.

Ganlu (甘露) 359–364 Jianyuan (建元) 365–385 ¹ Fu Sheng was posthumously given the title "wang" even though he had reigned as emperor.