Service under the Jin dynasty

However, Yao Xiang did not get along with Jin's leading commander, Yin Hao. In 353, Yin Hao was concern with Yao Xiang's autonomy and wanted to kill him. In his second assassination attempt, Yin Hao's general Wei Jing (魏憬) led an ill-fated ambush against Yao Xiang and was killed. After his death, Wei Jing's family continuously visited Yao Xiang and Yin Hao's base in Shouchun, causing much worry for Yao Xiang. Yao Xiang sent Quan Yi to talk to Yin Hao regarding the recent turn of events.^[2]

During their meeting, Yin Hao said to Quan Yi, "General Yao and I are both servants of His Highness. We share both joys and sorrows. However, General Yao is often arbitrary, which is not what I am hoping for from him." Quan Yi replied, "Yao Xiang is an unmatched hero with tens of thousands under his wing. The reason he obeys the House of Jin is that he had heard of the court's virtue and its many wise ministers. Yet you, General, easily believe in slanders and estrange yourself from General Yao. I believe the root of suspicion lies in you." Yin Hao said, "General Yao is unruly in nature, sparing and punishing as he pleases. Furthermore, he had allowed one of his underling to steal my horse. Is this how a servant of the throne acts?" Quan Yi said, "General Yao serves the imperial dynasty, how could he possibly harm the innocent? But the treacherous have no place under the law, so what pity is there in killing them?" Yin Hao continued, "Then why steal my horse?" Quan Yi responded, “General, you had said that the General Yao is a powerful man, too difficult to control, and that you plan to subdue him one day. That was why he took your horse, in order to defend himself." Yin Hao laughed and said, "Now how could that be?"^[3]

Shortly after the talk, another northern expedition was held, but during the expedition, Yao Xiang rebelled and ambushed Yin Hao's army. Quan Yi followed Yao Xiang throughout his time roving the Central Plains until Xiang was killed by Former Qin forces in 357. Quan Yi joined Xiang's brother, Yao Chang in surrendering to Qin and serving their new state.^[4]

Intercepting Murong Chui

For the next decade, Fu Jian continued his conquest of China, eventually leaving the Jin dynasty as the last remaining state in China to oppose the Qin expansion. Fu Jian wanted to conquer the southlands and complete his unification, but this was met with heavy opposition from some prominent officials including Quan Yi, Fu Rong, Dao'an and Shi Yue in 382. Quan Yi argued that although Jin was weak, the alliance of Huan Chong and Xie An was strong, and their officials were still loyal to their dynasty. Quan Yi also submitted a petition to remonstrate Fu Jian, but his suggestions fell on deaf ears.^[10]

Fu Jian's string of success came to an end with a terrible defeat at the Battle of Feishui in 383. Although Fu Jian managed to return to the north, the effects of the battle were beginning to show, as the Murong clan began making their moves to break away from Qin. Murong Chui was persuaded by his son, Murong Nong to revive their fallen state of Yan in Liaodong. Chui agreed, and at Mianchi, he tricked Fu Jian into letting him move to the northern borders, supposedly to secure the area from revolts. Quan Yi saw through his ruse, and quickly told Fu Jian to recall him back to the capital. However, Fu Jian was confident in Murong Chui's loyalty and refused to do so.^[11]

Despite Fu Jian's rejection, Quan Yi was determined to stop Murong Chui from reaching the north. Quan Yi, without Fu Jian's knowledge, sent warriors to intercept Murong Chui at the bridge across the Yellow River south of Kongcang (空倉). Murong Chui suspected something was off, so instead of taking the bridge, he created rafts in order for he and his men to cross the river. Meanwhile, he had one of his officers, Cheng Tong (程同) to wear his clothes and ride his horse while leading his boy attendants to use the bridge. Quan Yi's men ambushed Cheng Tong, but he managed to escape, and so did Murong Chui.^[12]

Fall of Chang'an

In 384, Former Qin began to fall apart. Murong Chui broke away and formed Later Yan, while his nephew Murong Hong created Western Yan. Yao Chang would also later declare independence and form Later Qin that year. Fu Jian regretted not following Quan Yi's advice and asked him what their next move should be. Quan Yi told him, "The enemies would not last for long. Murong Chui is preoccupied in securing the east of the mountains, and will not pose a threat. Our primary concern should be within the capital region, where the Xianbei clans densely reside. You should deal with this immediately." Fu Jian agreed and handed out new appointments to his loyalists.^[13]

In 385, Western Yan forces were close to conquer Qin's capital of Chang'an. Fu Jian had fled the city, promising to return with an army to save it. However, Fu Jian never returned, as he was captured by Later Qin forces and later executed. Meanwhile, Western Yan forces eventually overwhelmed the defenses, prompting Fu Jian's son, Fu Hong (苻宏) to abandon the capital. Quan Yi also fled the city with many others including Xue Zan, Huangfu Fu (皇甫覆), Zhao Qian (趙遷) and Duan Keng (段鏗) over to Later Qin.^[14]