Before and during Yao Changs reign

Yao Xing was born in 366, when his father Yao Chang was a general under the Former Qin emperor Fu Jiān. (Who his mother was is open to interpretation; Yao Chang's wife, the later Empress She, was mentioned as his mother, but when Yao Xing later became emperor, he posthumously honored one of Yao Chang's concubines, Consort Sun, as empress dowager, which allows an inference that he could have been born of Consort Sun but raised by Empress She, but there is no conclusive evidence.) Not much is known about his life under Former Qin rule, other than that when he grew older, he served as an assistant to Fu Jiān's crown prince Fu Hong (苻宏).

When Yao Chang declared a rebellion and established Later Qin in 384, Yao Xing was at the Former Qin capital Chang'an, and he immediately fled to his father. For the next several years, as Yao Chang fought with Former Qin and Western Yan, Yao Xing was often entrusted with guarding the base of operations (initially Beidi (北地, in modern Tongchuan, Shaanxi), later Chang'an after Western Yan captured and then abandoned it), while his father engaged in campaigns. In 386, after Yao Chang declared himself emperor, he created Yao Xing crown prince. He was considered to be firm and gracious, and he spent much time studying literature despite the work necessary in maintaining home base. In 392, while Yao Chang was away on a campaign, Yao Xing, at the suggestion of the general Yao Fangcheng (姚方成), executed a number of Former Qin generals whom Yao Chang had taken captive earlier. While Yao Chang was angry on the surface, he appeared to be secretly happy that Yao Xing realized the danger that these generals posed. In 393, when the Former Qin emperor Fu Deng attacked the Later Qin vassal Dou Chong, Yao Chang, at the suggestion of the prime minister Yin Wei (尹緯), sent Yao Xing against Fu Deng, in order to establish Yao Xing's authority over the troops. Yao Xing was able to stop Fu Deng's attack on Dou fairly easily.

Around the new year 393, Yao Chang fell seriously ill. He told Yao Xing, on his death bed, to trust the several officials that he entrusted his administration with—Yin, Yao Huang (姚晃), Yao Damu (姚大目), and Di Bozhi (狄伯支). When Yao Huang asked Yao Chang for strategies to defeat Fu Deng, Yao Chang refused to answer, merely stating that he trusted that Yao Xing would be able to accomplish it. He soon died, and Yao Xing succeeded him, although initially not keeping Yao Chang's death a secret and entrusting the troops to his uncles Yao Xu (姚緒) and Yao Shuode (姚碩德) and his brother Yao Chóng (姚崇), while preparing a campaign against Former Qin.

Early reign: establishment of Later Qin as regional power

Despite Yao Xing's hopes of keeping his father's death a secret, Fu Deng received news of it anyway—and immediately prepared a major attack against Later Qin. Fu Deng had his brother Fu Guang (苻廣) defend the base of Yongcheng (雍城, in modern Baoji, Shaanxi) and Fu Chong defend the base of Hu Kong Castle (胡空堡, in modern Xianyang, Shaanxi), and, in his anxiety, did not make sure that his army had sufficient water supply. Yao Xing set up his army at Mawei (馬嵬, in modern Xianyang, Shaanxi) to prevent Former Qin forces from reaching the river near Mawei, and Former Qin forces were stricken by thirst, but still fought harder. Yao Xing initially ordered Yin to be cautious, but Yin, realizing the trouble the Former Qin forces were already in and believing that morale would be destroyed if he undertook a cautious strategy, fought back fervently, and the Former Qin forces collapsed. Upon hearing the defeat, Fu Deng's brother Fu Guang (苻廣) and son Fu Chong abandoned the two bases that they were holding, and Fu Deng was unable to recapture them. He then sought help from the King of Western Qin, Qifu Gangui, who sent a relief force headed by Qifu Yizhou (乞伏益州). As Fu Deng sought to join up with Qifu Yizhou, Yao Xing ambushed and captured him, and then executed him. He disbanded Fu Deng's troops and gave Fu Deng's Empress Li to Yao Huang. Fu Deng's crown prince Fu Chong would assume imperial title and attempt to resist Later Qin a few months longer, but later in the year died in battle against Western Qin after Qifu Gangui turned against him, ending Former Qin. Later Qin assumed nearly all of Former Qin's remaining territory. Around the new year 395, Later Qin established peace with Later Yan, thus obviating likelihood of war on the eastern border—although later in 395, when Later Yan's crown prince Murong Bao carried out a disastrous campaign against Northern Wei's King Tuoba Gui, Later Qin sent a relief force to aid Northern Wei, although Later Qin forces did not actually engage Later Yan. Further, in 397, with Later Yan under heavy attack by Northern Wei after its founding emperor Murong Chui died and was replaced by Murong Bao, Later Qin refused to provide aid to Later Yan.

Later in 397, Empress Dowager She died. Yao Xing was described to be in such great mourning that he was unable to handle matters of state for some time. After that had passed, however, he continued to wear mourning clothes.

Overall, during this period, Yao Xing was described by historians as diligent and willing to listen to different opinions, ruling the empire efficiently. He engaged in a number of campaigns on the various borders, enlarging Later Qin's territories and influence.

In 399, Yao Xing sent his brother Yao Chóng the Duke of Qi and the general Yang Foxong (楊佛嵩) to attack the important Jin city of Luoyang, and in winter 399 captured Luoyang and the surrounding cities.

Also in 399, Yao Xing, in response to astrological signs that were considered signs of disaster, stopped claiming the title of emperor, instead using the title "Heavenly King" (Tian Wang), to show humility to the gods. He also accordingly demoted his officials and noble by one rank.

In 400, Yao Xing sent his uncle Yao Shuode the Duke of Longxi to launch a major attack against Western Qin. Despite Western Qin's initial success in cutting of Yao Shuode's supply line, Yao Xing himself led a force to aid yao Shuode, defeating Western Qin's king Qifu Gangui in battle, nearly capturing Qifu Gangui's entire army and proceeding to take most of Western Qin's cities. Qifu Gangui himself surrendered to Southern Liang's king Tufa Lilugu, thus temporarily ending Western Qin's existence. In fall 400, believing that he was being suspected by Tufa Lilugu, Qifu Gangui fled from Southern Liang and surrendered to Later Qin. Yao Xing created him the Marquess of Guiyi and, in 401, took the unusual action of giving Qifu Gangui his army back and ordering him to defend his old capital Wanchuan (苑川, in modern Baiyin, Gansu), and while Qifu Gangui was in name a Later Qin general, he acted independently at times.

Later in 401, Yao Xing, under suggestion from Yao Shuode, launched a major attack against Later Liang. To avoid conflict, Tufa Lilugu ordered Southern Liang forces to yield a path for Later Qin forces, and Yao Shuode therefore easily reached the Later Liang capital Guzang (姑臧, in modern Wuwei, Gansu), putting the city under siege. Southern Liang, Northern Liang, and Western Liang all sent messengers submitting as vassals. After two months of siege, Later Liang's emperor Lü Long also submitted as a vassal, and was given the title Duke of Jiankang, although he remained in control of Guzang and continued to use the Heavenly King title internally as well. Northern Liang's duke Juqu Mengxun became so apprehensive that he offered to yield his territory and relocate his entire army into Later Qin proper, but later reneged on the promise, although he remained Later Qin vassal for years. (Despite their status as Later Qin vassals, however, the various Liang states continued to battle against each other.)

Middle reign: entrenchment and stagnation

Around the new year 402, Northern Wei attacked the Later Qin vassal Mo Yigan (沒奕干), and this led to the breakdown of relations between Northern Wei and Later Qin. When Northern Wei's Emperor Daowu (Tuoba Gui) sought marriage with Later Qin, Yao Xing, because of this and because he heard that Emperor Daowu already had Empress Murong as his wife, refused. In summer 402, Yao Xing personally led a major attack against Northern Wei, which had by this point taken over nearly all of Later Yan's territory north of the Yellow River. In fall 402, Yao Xing's forward commander Yao Ping (姚平) the Duke of Yiyang was surrounded by Northern Wei's Emperor Daowu at Chaibi (柴壁, in modern Linfen, Shanxi), and despite counterattacks by both Yao Ping and Yao Xing, the Northern Wei siege became increasingly tighter, and in winter 402, Yao Ping and his army were captured following a failed attempt to break out, ending Yao Xing's campaign against Northern Wei.

Also in 402, Yao Xing created his concubine Consort Zhang empress. He also created his son Yao Hong as crown prince and other sons as dukes. (Yao Xing had long wanted to create Yao Hong, described as kind, loving, and studious, as crown prince, but hesitated because Yao Hong was also regarded as having a weak personality and prone to illnesses.)

Around this time, Yao Xing also appeared to have become a devout Buddhist, under the influence of the monk Kumarajiva. This appeared to have a major influence on his actions later on—as he appeared to avoid decisive actions that may lead to many deaths, while trying to act gently toward his enemies. This had an unfortunately deleterious effect on his empire, which, for the most part, stopped expanding. In 405, he gave Kumaraijiva an honorific title, treating him like a god, and often led his officials in listening to Kumaraijiva's sermons. At his request, Kumarajiva translated more than 300 sutras into Chinese. Yao Xing also built many towers and temples. Because of his influence, it was described that 90% of the population became Buddhists.

In 403, with his Later Liang state continuously under attack by Northern Liang and Southern Liang, Lü Long surrendered the Guzang region—the only territory still remaining under Later Liang control—to Later Qin, thus ending Later Liang. Yao Xing moved Lü Long and his clan to Chang'an and made him and his brother Lü Chao (呂超) officials. However, because Northern Liang and Southern Liang were only nominal vassals, Guzang was effectively a lone island of Later Qin control. In 404, Southern Liang's king Tufa Rutan (Tufa Lilugu's brother) stopped claiming kingly title and using his own era name, in a further showing of submission to Later Qin, although internally he remained effectively independent.

In 405, at the request of the Jin general Liu Yu, Yao Xing returned 12 commanderies that had switched their allegiance from Jin to Later Qin during the Jin civil war from 398 to 405, despite his officials' opposition. (This gesture, however, would not be reciprocated by Liu, who would destroy Later Qin after Yao Xing's death.)

In 406, in response to Tufa Rutan's tribute of 3,000 horses and 30,000 sheep, Yao Xing became so touched that he yielded Guzang to Tufa Rutan, thus ending Later Qin's actual control of the Guzang region.

In 407, believing that Qifu Gangui was becoming difficult to control, when Qifu Gangui arrived in Chang'an for an official visit, he detained Qifu Gangui to be a civilian official, while giving command of Qifu Gangui's army to Qifu Gangui's heir apparent, Qifu Chipan.

Later in 407, Later Qin and Northern Wei agreed to peace—returning previously captured generals to each other. The Later Qin general Liu Bobo (who would later change his name to Helian Bobo), who was then in charge of Shuofang (朔方, in modern Ordos, Inner Mongolia), because his father Liu Weichen (劉衛辰) had been killed by Northern Wei forces in 391, became angry and declared a rebellion, establishing Xia. Liu Bobo used guerrilla tactics against Later Qin, wearing Later Qin's armies and cities down. From this point on, Later Qin began to decline.

Late reign: gradual weakening of Later Qin

In 407, Murong Chao, the emperor of Southern Yan, whose mother and wife were then in Later Qin, requested to have them delivered to Southern Yan. Yao Xing agreed to do so if Murong Chao would agree to be a vassal and either deliver Former Qin palatial musicians (who were taken by Western Yan and eventually passed through Later Yan and then Southern Yan) or 1,000 Jin citizens to Later Qin, before his request would be agreed. Murong Chao agreed to yield as vassal, and delivered the musicians to Later Qin. Yao Xing then delivered his mother and wife to him, along with gifts.

Also in 407, Qiao Zong, who had taken control of Jin's Yi Province (modern Chongqing and Sichuan) and declared himself the King of Chengdu, became a Later Qin vassal.

In 408, noticing that Southern Liang was under severe attack by its neighbors (including having suffered a terrible defeat to Xia in 407), Yao Xing launched a campaign to try to destroy Southern Liang, despite opposition by his official Wei Zong (韋宗), who felt that Tufa Rutan would not be defeated easily. He commissioned his son Yao Bi (姚弼) the Duke of Guangping along with Qifu Gangui and Lian Cheng (斂成) to attack Southern Liang, while simultaneously commission Qi Nan (齊難) to attack Xia. Both ventures ended badly. Yao Bi and later Yao Xian (姚顯) the Duke of Changshan were defeated by Tufa Rutan, and Yao Xing was forced to agree to a new peace with Southern Liang while having lost prestige based on the defeat. Even more disastrous was the Qi's mission, however, as Qi fell into a trap laid by Liu Bobo and was captured with his entire army, causing all of modern northern Shaanxi to fall into Xia hands. Later in 408, Tufa Rutan effectively repudiated his vassal status by again claiming the title King of Liang (instead of the Later Qin-created title of Duke of Guangwu) and changing era name.

Around this time, there also began to be increasing tendencies by Yao Xing's brothers and sons to plot to take over power. For example, in 409, his brother Yao Chōng (姚沖, note different tone than another brother) tried to force Di Bozhi to join him in a plot to attack Chang'an, and when Di refused, poisoned Di to death, but was discovered later and forced to commit suicide.

Also in 409, Qifu Gangui escaped and returned to Wanchuan to join his son Qifu Chipan. He soon redeclared independence and reestablished Western Qin as its king. He soon launched several campaigns against Later Qin and inflicted substantial damage, although he would apologize in 411 and again declared himself a Later Qin vassal. Later that year, however, he resumed his attacks.

Later in 409, the Jin general Liu Yu launched a major attack on Southern Yan, which sought aid from Later Qin. Initially, Yao Xing sent messengers to try to persuade Liu Yu to withdraw, and also sent a relief force commanded by Yao Qiang (姚強), but was forced to withdraw Yao Qiang's force when he suffered a major loss at Liu Bobo's hands and was nearly captured. Without aid from Later Qin, Southern Yan fell to Jin in early 410.

Later in 410, at Qiao Zong's request, Yao Xing sent an army commanded by Gou Lin (苟林) to join Qiao Zong's army, commanded by Huan Qian (桓謙) and Qiao Daofu (譙道福) to attack Jin's Jing Province (荊州, modern Hunan and central Hubei). However, Liu Yu's brother Liu Daogui (劉道規) defeated both armies, killing Huan Qian and forcing Gou to flee.

As of 411, Yao Bi, who was greatly favored by Yao Xing, was deep into a conspiracy to try to undermine the crown prince Yao Hong.

In 412, Qifu Gangui was assassinated by his nephew Qifu Gongfu (乞伏公府), the son of the founding king Qifu Guoren. Many Later Qin officials try to persuade Yao Xing to take the opportunity, as Qifu Gongfu and Qifu Chipan battled for control of the state, to attack Western Qin. Yao Xing refused, believing it improper to attack a state that was still mourning.

Also in 412, Yao Xing created his concubine Consort Qi empress. (No historical record gave the date when Yao Xing's first empress Empress Zhang died, but presumably she had by this point.)

In 413, Liu Yu's general Zhu Lingshi (朱齡石) attacked Qiao Zong's Western Shu state and destroyed it, reannexing it to Jin. Yao Xing, although Western Shu's suzerain, was unable to aid it.

In 414, Yao Bi made several attempts to be made crown prince by having officials close to him suggesting Yao Xing to replace Yao Hong with him. Yao Xing refused, but did not rebuke Yao Bi. Yao Xing grew seriously ill that year, and Yao Bi planned a coup to take over. His brother Yao Yu revealed his plot to the other brothers Yao Yi, Yao Huang, Yao Chen, and Yao Xuan, who mobilized their own forces to be ready to attack Yao Bi if necessary. Yao Xing was forced to relieve Yao Bi of his posts, and the other sons demobilized and arrived at Chang'an for an official visit. The sons accused Yao Bi of many crimes, but Yao Xing took no further action. Indeed, in 415, Yao Bi retaliated by falsely accusing Yao Xuan of crimes, and Yao Xing arrested Yao Xuan.

In summer 415, the Jin general Sima Xiuzhi (司馬休之), having been forced to escape after Liu Yu attacked him, fled to Later Qin. Yao Xing commissioned Sima Xiuzhi with an army to let him harass Jin borders, despite warnings by his officials of a prophecy that the Simas would regain Guanzhong and the Luoyang region.

In fall 415, Yao Xing fell ill again, and Yao Bi secretly gathered forces again to plan a coup. Yao Xing found out and arrested Yao Bi, but at Yao Hong's urging did not execute him but instead released him.

In winter 415, Yao Xing sent his daughter, the Princess Xiping, to Northern Wei to be married to Emperor Daowu's son Emperor Mingyuan, in order to affirm the alliance between the two states. Emperor Mingyuan welcomed her with the ceremony due an empress. However, Princess Xiping was unable to forge a golden statue, as required by Tuoba Tribe traditions to be a sign of divine favor, to become an empress, so she was only created an imperial consort, but she was treated with the honors due an empress.

In 416, Yao Xing went on a trip to Huayin (華陰), near Chang'an, and fell ill on the trip and headed back to Chang'an. His attendant Yin Chong (尹沖) -- one of Yao Bi's supporters—planned to then assassinate Yao Hong as Yao Hong would come out of the city to welcome Yao Xing. Yao Hong's supporters received news of this and persuaded Yao Hong not to come out to welcome Yao Xing. Yin's assistant Yao Shami (姚沙彌) then tried to persuade Yin to take Yao Xing and join with Yao Bi to seize power, but Yin hesitated and did not do so. Once Yao Xing returned to the Chang'an palace, he transferred power to Yao Hong and ordered Yao Bi arrested. Meanwhile, Yao Xing's son Yao Geng'er (姚耕兒), believing that Yao Xing had died, persuaded his brother Yao Yin (姚愔) the Duke of Nanyang to start a coup, and Yao Yin joined with Yin Chong (perhaps in anticipatory support of Yao Bi's claims) to attack the palace, battling with Yao Hong's troops. Yao Xing, despite his illness, made an appearance and announced an edict ordering Yao Bi to commit suicide. As soon as Yao Yin's troops saw Yao Xing, they abandoned Yao Yin. That night, Yao Xing entrusted Yao Hong's administration to his brother Yao Shao (姚紹) the Duke of Dongping, Liang Xi (梁喜), Yin Zhao (尹昭), and Lian Manwei (斂曼嵬), and he died the next day. Yao Hong succeeded him, but he soon had to face even more challenges from his brothers and cousins as well as attacks by Xia and Jin, and by 417 Later Qin had fallen to Jin.

Era names

• Huangchu (皇初 huáng chū) 394–399

• Hongshi (弘始 hóng shǐ) 399–416

Personal information

• Father

　• Yao Chang (Emperor Wucheng)

• Mother

　• Empress She (but might be Consort Sun)

• Wives

　• Empress Zhang (created 402)

　• Empress Qi (created 412)

• Children

　• Yao Hong (姚泓), the Crown Prince (created 402), later emperor

　• Yao Yi (姚懿), the Duke of Taiyuan (created 402)

　• Yao Bi (姚弼), the Duke of Guangping (created 402, forced to commit suicide 416)

　• Yao Huang (姚洸), the Duke of Chenliu (created 402)

　• Yao Xuan (姚宣), Duke (created 402, executed by Yao Shao 416)

　• Yao Chen (姚諶), Duke (created 402)

　• Yao Yin (姚愔), the Duke of Nanyang (created 402, executed by Yao Hong 416)

　• Yao Pu (姚璞), the Duke of Pingyuan (created 402, executed by Liu Yu 417)

　• Yao Zhi (姚質), Duke (created 402)

　• Yao Kui (姚逵), Duke (created 402)

　• Yao Yu (姚裕), Duke (created 402)

　• Yao Guoer (姚國兒), Duke (created 402)

　• Yao Geng'er (姚耕兒)

　• Yao Huangmei (姚黃眉), Duke of Longxi of Northern Wei

　• Princess Xiping, concubine of Emperor Mingyuan of Northern Wei

生平

姚興在前秦時任太子舍人。白雀元年（384年），姚萇在渭北馬牧稱萬年秦王，建後秦，姚興時在長安，冒險出走與父親會合。建初元年（386年），姚萇在奪得長安（今陝西西安）後稱帝，就立了姚興為皇太子。其時姚萇屢次在外與前秦對抗，姚興就經常留鎮長安以統後事。其時又與太子中舍人梁喜及太子洗馬范勖講論經籍，不以兵戎廢業，當時的人亦受他們影響。

消滅前秦

建初八年（393年）十二月，姚萇去世，死前命太尉姚旻、僕射尹緯、姚晃、將軍姚大目及尚書狄伯支為輔政大臣，並向姚興說：「若有人謗毀這幾位大臣，小心不要聽信。你以仁管教子女，以禮對待大臣，以信處事，以恩治民，這四項你能做到，我就不憂心了。」姚萇死後，姚興秘不發喪，分命姚緒、姚碩德及姚崇駐安定、陰密及長安，自己就自稱大將軍，領兵進攻前秦。

次年春，前秦皇帝苻登聽聞姚萇已死即十分高興，又輕視姚興，隨即率眾東進。至夏季，苻登要進攻廢橋，尹緯則受命支援守馬嵬堡的姚詳，尹緯於是據守廢橋等待前秦軍。前秦軍因無法取得水源而缺水，兩三成士兵更因而渴死，於是急攻尹緯希望能奪取水源。姚興當時認為苻登已是窮寇，於是派狄伯支命令尹緯要持重拒戰，不要輕易與前秦軍決戰。不過尹緯認為姚萇新死，人心恐懼不安，應當用盡力量消滅敵人，安定眾心。尹緯於是與苻登決戰，終大敗前秦軍，苻登因兵眾潰散而逃走，逃到馬毛山。戰後，姚興才正式發喪，並在槐里（今陝西興平東南）即位為帝，改元「皇初」。七月，姚興進攻苻登並在馬毛山南作戰，擒殺苻登，並解散其部眾。不久繼位的前秦皇帝苻崇因被乞伏乾歸逼逐而聯結楊定進攻乞伏乾歸，卻遭對方所殺，前秦正式滅亡。

對外擴張

皇初七年（397年），姚興率兵進攻東晉控制的湖城，弘農太守陶仲山及華山太守董邁都投降。姚興於是進至陝城（今河南陝縣），並攻下上洛（今陝西商洛市）。另又分遣姚崇進攻洛陽（今河南洛陽），因晉河南太守夏侯宗之守金鏞城而未能攻克，於是改攻柏谷，強遷兩萬多戶流民西歸。及至皇初九年（399年），姚興命姚崇及楊佛嵩再攻洛陽，守將辛恭靖堅守一百多日後失守，後秦奪得洛陽。取洛陽後，淮河、漢水以北各城大多都向後秦請降，並送人質。

弘始二年（400年），姚碩德進攻西秦，西秦王乞伏乾歸率眾抵抗，兩軍對峙期間姚碩德軍中柴草缺乏，姚興就暗中領兵支援。乞伏乾歸知道姚興派軍前來，於是命慕兀率二萬中軍屯柏楊（今甘肅清水縣西南），羅敦率外軍屯侯辰谷，自己領數千輕騎等候秦軍。不過其夜遇上大風和大霧，乞伏乾歸與慕兀的中軍失去聯絡，被逼與外軍會合。天亮後，乞伏乾歸就與後秦軍作戰，終大敗並逃返苑川（今甘肅榆中縣北），後秦軍受降共三萬六千多人，姚興則進軍枹罕（今甘肅臨夏市）。乞伏乾歸初降禿髮利鹿孤，但因怕不為對方所容，最終決定歸降後秦。

弘始三年（401年），姚興命姚碩德進攻後涼，並兵圍後涼首都姑臧（今甘肅武威）。後涼王呂隆被逼請降。而在後秦攻涼時，西涼李暠、南涼禿髮利鹿孤及北涼沮渠蒙遜都遣使向後秦請降。直至弘始五年（403年），後涼被南涼和北涼所逼，最終請後秦派軍迎來歸附，姚興因而派了齊難等人到姑臧，駐兵當地並送呂氏宗族內徙長安，吞併後涼。另外在攻打後涼姑臧時，連帶的將名僧鳩摩羅什請回長安。爾後為鳩摩羅什講解《法華經》，建造｢長安大寺｣。鳩摩羅什於長安圓寂，其生前將大乘佛教的主要經典(如《中論》、《法華經》、《維摩詰經》等)譯為漢文。

柴壁之戰

北魏君主拓跋珪曾經送一千匹馬到後秦請婚，姚興原先答應，但知拓跋珪已立了後，於是拒絕並留下使者賀狄幹。弘始四年（402年），北魏將領拓跋遵進攻高平（今甘肅固原），沒弈幹拋棄部眾，帶著數千騎兵及赫連勃勃逃到秦州。北魏軍追擊至瓦亭仍未追上，於是盡遷高平的物資回國；及後北魏平陽太守貳塵又進攻河東。北魏的一系列軍事行動震動長安，關中各城日間也緊閉城門，姚興於是在城西閱兵，並做好戰爭準備。同年，姚興派姚平及狄伯支等率四萬步騎兵進攻北魏，姚興則親率大軍在後。北魏帝拓跋珪則命拓跋順及長孫肥統六萬騎兵為先鋒，自己也率大軍在後以作抵抗。姚平用了六十多天攻陷了北魏屯積糧食的乾壁，又派二百精騎偵察魏軍，卻為長孫肥襲擊，所有人都被生擒。姚平因而後撤，又遭拓跋珪追擊，並在柴壁（今山西襄汾縣西南）被追上；姚平當時據柴壁城固守，北魏軍則圍困城池。姚興於是自領四萬七千兵營救姚平，並打算佔領天渡以運糧支援姚平。不過北魏加強了包圍圈，又在汾水建浮橋，在汾水西岸築圍堵截姚興援軍，務求引姚興取道汾東，經長達三百多里而缺乏小路通行的蒙坑進攻。而姚興到蒲阪後因怕魏軍強盛，很久才正式進攻。及後姚興在蒙坑以南與拓跋珪所率三萬步騎兵作戰，後秦軍共千多人被殺，姚興被逼退走四十多里，而姚平亦未能突圍。接著拓跋珪分兵各據險要，不讓後秦軍接近柴壁。姚興駐屯汾西，在汾水上游放木材打算沖毀北魏浮橋，但木材都被魏軍截取。至十月，姚平軍需用盡，在夜間試圖向西南方突圍，姚興列兵汾西，點起烽火和擂鼓響應，不過姚興欲救姚平盡力突陣，姚平反望姚興攻圍接應，兩軍雖然能夠以叫喊相通，但始終都沒能壓逼圍城魏軍。姚平最終無法成功突圍，於是率眾投水自殺，然而拓跋珪卻都派人潛下水捕捉，赴水諸將與城中狄伯支、唐小方等人及兩萬多兵眾都被俘。姚興只能見城中軍隊束手就擒而無力支援，全軍都哀傷痛哭，哭聲震動山谷。接著姚興數度派遣使者求和，但都被拒，魏軍更乘勝進攻蒲阪。防禦蒲阪的姚緒固守不戰，又正因柔然要進攻北魏，拓跋珪才撤兵。

夏國內擾

弘始九年（407年），北魏歸還柴壁之戰中被俘的唐小方等人，姚興又以良馬千匹贖回狄伯支，與北魏通和。赫連勃勃因後秦與北魏連和而大怒，竟搶奪了柔然送給後秦的八千匹馬，並襲殺沒弈幹叛變，稱大夏天王，建夏國。赫連勃勃隨後又攻破鮮卑薛幹等三部，並進攻後秦三城以北諸戍，後秦將楊丕、姚石生等都被殺，接著又侵掠嶺北，令嶺北各城城門白天也要緊閉。姚興此時感嘆：「我不聽黃兒（姚興弟姚邕小字）的話，才弄成今天這樣子。」

隨後禿髮傉檀大敗於赫連勃勃，名將折損達六七成，接著成七兒及梁裒、邊憲等又先後謀反，姚興見其並受外憂外患夾擊，不顧尚書郎韋宗的勸阻和吏部尚書尹昭命北涼及西涼進攻禿髮傉檀的建議，堅持分兵兩道進攻夏和禿髮傉檀。姚興於弘始十年（408年）派了齊難領二萬騎兵攻夏，又派姚弼、斂成及乞伏乾歸攻禿髮傉檀，更寫信給禿髮傉檀聲稱姚弼等其實只是配合齊難進攻夏國的行動，禿髮傉檀不作防備。不過姚弼等到姑臧後反被禿髮傉檀的奇兵擊敗，後又特地釋放牛羊引誘後秦軍掠奪，大敗秦軍。作為後繼的姚顯知姚弼兵敗，加快趕到姑臧，並命孟欽等五名擅長射擊的人於涼風門挑戰，卻遭南涼材官將軍宋益擊殺。姚顯見此委罪於斂成，派使者向禿髮傉檀謝罪，撫慰河西後就撤還。而禿髮傉檀亦派使者徐宿向後秦謝罪。不過在當年又再稱涼王。

而赫連勃勃知齊難來攻，於是退守河曲。齊難見赫連勃勃仍在很遠，於是先行縱兵野略；赫連勃勃因而潛軍來襲，俘殺七千多人，齊難逃走但在木城遭赫連勃勃生擒，其餘將士亦被俘。戰後嶺北共計有數萬人歸附赫連勃勃。弘始十一年（409年），姚興再派姚沖及狄伯支率四萬騎再攻夏，但姚沖竟圖謀反，並殺了不肯支持的狄伯支，姚興終賜死姚沖。同年，姚興親自率軍攻夏，至貳城後就派姚詳、斂曼嵬及彭白狼分督租運。其時諸軍未集合，而赫連勃勃乘虛來襲，姚興恐懼之下打算逃到姚詳那裏，但被右僕射韋華勸止。姚興派姚文宗等迎戰，雖將領姚榆生被擒，但在姚文宗力戰之下也成功擊退赫連勃勃。姚興唯有留五千禁軍助姚詳守貳城，自己撤還長安。

赫連勃勃攻破了敕奇堡、黃石固及我羅城。次年又派胡金纂攻平涼，雖然姚興親自率軍擊殺胡金纂，但赫連勃勃侄赫連羅提又攻下定陽，殺四千多人並俘姚廣都。當時秦將曹熾、曹雲及王肆佛等被逼領數千戶內徙，姚興就讓他們住在湟山及陳倉。接著赫連勃勃又進攻隴，攻略陽太守姚壽都守的清水城，姚壽都棄城奔上邽，而赫連勃勃就遷了城中一萬六千戶人到大城。姚興試圖從安定追擊赫連勃勃，但追不上。及後赫連勃勃仍屢屢侵擾後秦，但姚興都無法消滅夏國。

姚弼爭儲

姚興子廣平公姚弼得父親寵愛，任雍州刺史，出鎮安定時天水人姜紀接近姚弼，並勸他巴結姚興左右以望還朝，姚弼於是巴結常山公姚顯。至弘始十三年（411年），姚興就召了姚弼回長安，讓他為尚書令、侍中、大將軍。姚弼於是擔當將相要職，更心引見人才，收結朝士，形成了一股比太子姚泓更大的勢力，更有圖取其太子之位。後來姚弼因為厭惡姚泓親信姚文宗，就誣陷他有所怨言，並讓侍御史廉桃生作證。姚興信以為真，一怒之下就賜死姚文宗。朝中大臣於是都不敢再說姚弼不是了。

因著對姚弼的寵愛，姚興對姚弼幾乎言聽計從，於是機要職位都由姚弼親信出任。當時右僕射梁喜、侍中任謙及京兆尹尹昭就找機會向姚興表示姚弼有奪嫡的志向，指出姚興不當的寵愛他，令傾險無賴的人都在其身邊，又說民間都說姚興有廢立之意，三人同時表示反對易儲。姚興立即否認有易儲計劃，三人就是更勸姚興削減姚弼權力並除去其身邊黨羽，既保姚弼，亦保國家。姚興聽後就沉默不言。

弘始十六年（414年），姚興病重，太子姚泓屯兵東華門，並在諮議堂侍疾。當時姚弼卻意圖作亂，招集了數千人並藏匿在其府中。姚裕當時與任謙、梁喜等人都掌禁軍守衞皇宮，而姚裕就派使者將姚弼謀反的行狀告知各個外藩，於是駐蒲阪的姚懿、洛陽的姚洸及雍城的姚諶都將要領兵入長安討伐姚弼。此時姚興病情好轉，召見了群臣，征虜將軍劉羌向姚興泣告姚弼謀反之事，尹昭等都建議姚興即使不按法處死，也應削其權力，讓他散居藩國。姚興仍然欣賞才兼文武的姚弼，不忍殺他，於是免去其尚書令職位，以大將軍、廣平公身份還第。

及後姚懿、姚洸、姚宣及姚諶來朝，見面時姚宣哭請姚興按法處置姚弼，但姚興拒絕。撫軍東曹屬姜虯也上書指姚弼雖然被姑息，但其黨羽仍然活躍，姚弼變亂的心是不會變的，更請消除姚弼黨羽，以絕禍根。姚興就問梁喜：「天下的人全都以我兒子作為口實，要如何處理？」梁喜則說：「真的如姜虯所言，陛下應該早點有個決定。」姚興又沉默不言。

弘始十七年（415年），姚弼知姚宣在父親面前說自己不是，十分憤恨，於是就向姚興誣陷姚宣。姚興又相信，並召見當時到了長安的姚宣司馬權丕，責怪他沒有好好匡輔姚宣並要處死他。但權丕竟然捏造了姚宣的罪狀報告姚興。姚興於是大怒，收捕了姚宣並派姚弼率兵三萬出鎮秦州。尹昭知道後向姚興指讓姚弼統大軍在外，一旦姚興去世，就會是太子姚泓的大大威脅，試圖勸止姚興，但姚興不聽。

同年，姚興食五石散中毒，姚弼卻稱病不朝，又再次在府中招集兵眾。姚興知道後大怒，殺了姚弼黨羽殿中侍御史唐盛及孫元。姚泓卻在怪責自己，請姚興殺了他，或處之外藩。姚興於是召了姚讚、梁喜、尹昭及斂曼嵬，和他們討論後囚禁了姚弼並準備殺了他，又要將姚弼黨羽全部治罪。不過姚泓請命之下，都將他們寛恕。

弘始十八年（416年），姚興出行華陰，留姚泓監國。及後姚興病重回長安，姚弼黨羽尹沖等仍想發難，想趁姚泓出迎姚興而將其殺害，但姚泓只在黃龍門拜迎。其時尚書姚沙彌更意圖劫奪姚興到廣平公府，以姚興招引眾人支持，從而從姚泓手中奪去儲君之位。尹沖雖不從，但仍然考慮隨姚興乘輿入宮中作亂，只是未知姚興生死而不敢行動。姚興則命姚泓錄尚書事，並命姚紹及胡翼度掌禁軍，又命斂曼嵬收去姚弼府中的武器。

不久，姚興病情更趨嚴重，姚興妹南安長公主去探望他也得不到回應，姚興幼子姚耕兒就向哥哥姚愔報告姚興已死，叫他快點做決定。姚愔於是就帶其他的士兵攻端門，斂曼嵬領兵抵禦，而胡翼度就關上宮中四門。姚愔派壯士爬上門並進入宮內，並走到馬道。時在諮議堂侍疾的姚泓命斂曼嵬登武庫抵禦，而太子右衞率姚和都亦已率東宮士兵在馬道南駐屯。姚愔無法前進，只得燒毀端門。姚興此時竭力走到前殿，並下令賜死姚弼。禁軍見到姚興士氣大振，向姚愔軍發動進攻，姚和都也在後夾擊，最終姚愔軍潰敗，姚愔逃到驪山，呂隆則逃到雍城，尹沖及尹泓就南奔東晉。

姚興召姚紹、姚讚、梁喜、尹昭和斂曼嵬入寢宮，遺命他們為輔政大臣。姚興即逝世，享年五十一歲。諡文桓皇帝，廟號高祖，下葬偶陵。

為政措施

姚興曾命各郡國每年都上報一個品行純潔的孝廉，又留心政事，廣納百言，包容各種意見。即使只是說了一句姚興認為有益的建言，都會得到特別禮待。如杜瑾、吉默和周寶就曾因向姚興陳述當時國中大事而獲授要職。姚興又重文教，當時有姜龕、淳于岐及郭高等有大德的老儒士在長安教學，各有數百門生，其中有不少門生更遠道而來。而姚興就在處理政務以外的時間請姜龕等到東堂和他談論學問和技藝。當時一叫胡辯的人在當時仍是東晉佔領的洛陽授學，很多關中人都去拜師，姚興更下令各關守長盡量方便這些求學的人出入。種種措施都令後秦儒學興盛。

皇初九年（399年），姚興以國內天災頻頻，於是自降帝號，稱秦王；另又下令郡國將因戰亂而賣身為奴婢的人變回良人，更將幾個貪財官員誅殺，整頓官員風氣。及後又在長安建立法律學校，讓各郡縣散吏入讀，學成者就送回郡縣以處理形獄事項，又下令郡縣無法裁決的都上交廷尉處理。姚興更經常到諮議堂聽訟和作判決，大大減少了冤獄。

弘始三年（401年）呂隆向後秦請降後，姚興就迎在後涼的僧人鳩摩羅什入長安，並奉其為國師，奉之如神。鳩摩羅什在長安組織了大規模的翻譯佛經事業，姚興亦信了佛，於是群下都跟著信奉佛教，又吸引了五千多個僧人遠道而來。姚興又在永貴里建了佛塔、在中宮建了波若臺，佛教興盛，各州郡都受到佛教影響，至「求佛者十室而九。」

姚興在位後期，國庫不足，曾增加關隘和渡口的稅，又向鹽、竹、山林和木材徵稅。群臣曾勸諫但姚興認為能夠常出入關隘及取利於山水資源的都是富人，現在增稅其實只是取富人多餘的而彌補國家不足，並無不妥。

性格特徵

姚興生性儉約，所乘車馬都沒有黃金或玉石裝飾，以身作則之下，群下都崇尚清正廉潔。不過姚興卻喜歡打獵，常傷及農作物。杜挻及相雲曾分別作《豐草詩》及《德獵賦》以作暗示，姚興雖然明白並以黃金及布帛作賞賜，但始終改變不了打獵的習慣。

每當大臣去世，姚興都不會只按慣例在東堂發哀，而會親身去臨喪。

姚興十分看重親族，更對兩名叔叔姚碩德及姚緒十分恭敬。姚興降號為王時，本為王爵的姚碩德及姚緒應當降為公爵，但姚興不允，在二人再三辭讓下才得允許。姚興又曾下令所有官員取名時不得犯二人名諱，所有車馬、衣服及器玩都先給二人，自己只用次一等的，見面時行家人之禮，朝中大事亦必定先諮詢二人。姚沖叛變不遂殺了顧命大臣之一的狄伯支，姚興仍然顧念他是最小的弟弟，雄武絕人，還想對他寬容一次，不過在斂成規勸下，姚興想到他殺了狄伯支，就下書賜死姚沖。

家庭

后妃

• 張皇后

• 齊皇后

子女

• 太子姚泓，後秦末主

• 太原公姚懿

• 廣平公姚弼，弘始十八年（416年），謀亂失敗，賜死

• 陳留公姚洸

• 公爵姚宣

• 公爵姚諶

• 南陽公姚愔，416年被姚泓誅殺

• 平原公姚璞，永和（417年）投降劉裕，被殺

• 公爵姚質

• 公爵姚逵

• 公爵姚裕

• 公爵姚國兒

• 姚耕兒

• 北魏隴西公姚黃眉

• 西平公主

註釋