Emperor Taizong Of Tang

Emperor Taizong of Tang
Birth and death:	Jan. 23, 599–Jul. 10, 649
Family name:	Li (李)
Given name:	Shimin (世民)
Dates of reign:	September 4, 626–July 10 649
Temple name:	Taizong (太宗)
Posthumous name: (short)	Wen Huangdi (文皇帝)
Posthumous name: (full)	Wen Wu Dasheng Daguang Xiao Huangdi[1] 文武大聖大廣孝皇帝 [Listen ▶]
General note: Dates given here are in the Julian calendar. They are not in the proleptic Gregorian calendar. ———

Emperor Taizong of Tang (Chinese: 唐太宗; pinyin: táng tàizōng, January 23, 599 – July 10, 649), personal name Lǐ Shìmín (Chinese: 李世民), was the second emperor of the Tang Dynasty of China, ruling from 626 to 649. Since he encouraged his father, Li Yuan (Emperor Gaozu) to rise against Sui Dynasty rule at Taiyuan in 617 and subsequently defeated several of its most important rivals, including Xue Rengao the Emperor of Qin, Liu Wuzhou the Dingyang Khan, Wang Shichong the Emperor of Zheng, and Dou Jiande the Prince of Xia, he was ceremonially regarded as a cofounder of the dynasty along with Emperor Gaozu,^[2] This status was confirmed by the founding emperor of Southern Tang Emperor Liezu (Li Bian), who treated Emperors Gaozu and Taizong, as well as his adoptive father Xu Wen, all as founders of his state.^[3]

Tang became the dominant power in eastern Asia in 630, when Emperor Taizong sent his general Li Jing against Eastern Tujue , defeating and capturing its Jiali Khan Ashina Duobi and destroying Eastern Tujue power. Emperor Taizong subsequently took the title of "Heavenly Khan" (天可汗). Throughout the rest of Chinese history, Emperor Taizong's reign was regarded as the exemplary model against which all other emperors were measured, and his "Reign of Zhen'guan" (貞觀之治) was considered one of the golden ages of Chinese history and became required study for future crown princes. During his reign, Tang China flourished economically and militarily. Emperor Taizong was admired for surrounding himself with capable administrators, including the chancellors Fang Xuanling, Du Ruhui, and Wei Zheng, and for listening to their advice and welcoming their criticisms. Emperor Taizong's wife Empress Zhangsun also supported him and served as a capable assistant.^[4] The greatest praise given to one of his better-regarded successors, Emperor Xuānzong, was the epithet "Little Taizong" (小太宗).^[5]

Background

Li Shimin was born in 599 at Wugong (武功, in modern Xianyang, Shaanxi). His father Li Yuan the Duke of Tang, was a general of the Sui Dynasty and a nephew, by marriage, to Sui's founding emperor Emperor Wen. Li Shimin's grandmother, Duchess Dugu, was a sister of Empress Dugu Qieluo; both were daughters of Dugu Xin (獨孤信), a major general during the dynasty preceding Sui, Northern Zhou. Li Shimin's mother, Duchess Dou, was a daughter of Dou Yi (竇毅), the Duke of Shenwu, and his wife, Princess Xiangyang of Northern Zhou. Duchess Dou bore Li Yuan four sons, Li Jiancheng (an older brother to Li Shimin), and two younger brothers, Li Xuanba (李玄霸, died in 614) and Li Yuanji; and at least one daughter, Princess Pingyang. Li Yuan named Li Shimin "Shimin" as a shortened form of the phrase "save the earth and pacify the people" (濟世安民, jishi anmin). Li Shimin apparently showed talent early in his life, and in 613, the official Gao Shilian, impressed with his ability, gave him a niece (the later Empress Zhangsun) in marriage; he was 14 and she was 12.

In 615, when Emperor Wen's son and successor Emperor Yang was ambushed by Eastern Tujue forces at Yanmen (雁門, in modern Xinzhou, Shanxi), a general call was made for men to join the army to help rescue the emperor. Li Shimin answered that call and served under the general Yun Dingxing (雲定興), apparently with distinction. In 616, when Li Yuan was put in charge of the important city of Taiyuan (太原, in modern Taiyuan, Shanxi), he took Li Shimin there with him, leaving at least three other sons, Li Jiancheng, Li Yuanji, and Li Zhiyun (李智雲, by Li Yuan's concubine Lady Wan), at his ancestral home in Hedong (河東, in modern Yuncheng, Shanxi).

Participation in the Rebellion Against Sui Rule

Template:Sui-Tang Transition

Emperor Yang soon became dissatisfied with Li Yuan and Wang Rengong (王仁恭), the governor of Mayi Commandery (馬邑, roughly modern Shuozhou, Shanxi), because they were unable to stop the incursions of the Eastern Tujue and curb the growing strength of agrarian rebels. The Eastern Tujue supported Liu Wuzhou, the Dingyang Khan, who soon rose against Wang, killed him, and captured Emperor Yang's secondary palace near Taiyuan. At that time there had been prophecies throughout the empire that the next emperor would be named “Li,” and Emperor Yang had killed another official named Li Hun (李渾) and his clan over his fears that his nephew Li Min (李敏, the son-in-law of Emperor Yang's sister Yang Lihua, the Princess Leping) might succeed him. Li Yuan became fearful that he and his family might also be executed, and began to consider rebelling against the Emperor.

He was not aware that his son Li Shimin had also been secretly plotting rebellion with Li Yuan's associates Pei Ji and Liu Wenjing. Li Shimin sent Pei to inform Li Yuan of their plans, and to warn Li Yuan that if it were revealed that Li Yuan had consorted with some of Emperor Yang's ladies in waiting at the secondary Jinyang Palace (晉陽宮), which was under Pei’s supervision, all of them would be slaughtered. Li Yuan agreed to join them. After secretly summoning Li Jiancheng and Li Yuanji from Hedong, and his son-in-law Chai Shao (柴紹) from the capital Chang'an, he declared a rebellion, under the pretext of supporting Emperor Yang's grandson Yang You, the Prince of Dai, who was nominally in charge at Chang'an, with Emperor Yang at Jiangdu (江都, in modern Yangzhou, Jiangsu), as emperor. He appointed both Li Jiancheng and Li Shimin major generals and advanced southwest, toward Chang'an. Li Yuan also created Li Shimin the Duke of Dunhuang.

When Li Yuan arrived near Hedong, his army became bogged down by the weather. Food supplies were running low, and there were rumors that Eastern Tujue and Liu Wuzhou were about to attack Taiyuan. Li Yuan initially ordered a retreat, but at the insistence of Li Jiancheng and Li Shimin, continued to advance. After defeating Sui forces at Huoyi (霍邑, also in modern Yuncheng), Li Yuan left a small contingent to watch over Hedong and advanced across the Yellow River into Guanzhong (the Chang'an region). He sent Li Jiancheng to capture the territory around the Tong Pass region, to prevent Sui forces at Luoyang from reinforcing Chang'an, and Li Shimin north of the Wei River to capture territory there, while he led his own forces to Chang'an. Meanwhile, Li Shimin's sister (wife of Chai Shao) had also risen in rebellion in support of him, gathered a sizeable army and captured some cities. She joined forces with Li Shimin and her husband, Chai Shao. Li Yuan reconsolidated his forces and put Chang'an under siege. In the winter of 617, he captured Chang'an and placed Yang You on the throne as Emperor Gong of Sui. He had himself made regent (with the title of grand chancellor) and created the Prince of Tang. He created Li Shimin the Duke of Qin.

Li Yuan's control of the Chang'an region was contested almost immediately by the rebel ruler Xue Ju, the Emperor of Qin, who sent his son Xue Rengao toward Chang'an. Li Shimin was sent to resist Xue Rengao, and defeated him at Fufeng (扶風, in modern Baoji, Shaanxi). Xue Ju considered surrendering to Li Yuan, but was dissuaded from doing so by his strategist Hao Yuan (郝瑗).

Most of Sui territory did not recognize Emperor Gong and continued to regard Emperor Yang as the sovereign, not as a retired emperor. In the spring of 618, Sui's eastern capital Luoyang, where the officials in charge did not recognize Li Yuan's authority, was under attack from the rebel ruler Li Mi, the Duke of Wei. Li Yuan sent Li Jiancheng and Li Shimin to Luoyang, ostensibly to aid the Sui forces at Luoyang, but with the intention of discovering whether Luoyang might submit to him. The officials at Luoyang rebuffed his attempt at rapprochement, and Li Jiancheng and Li Shimin, not wanting to fight for control of Luoyang, withdrew. Li Yuan subsequently changed Li Shimin's title to Duke of Zhao.

In the summer of 618, news arrived at Chang'an that Emperor Yang had been killed at Jiangdu in a coup led by the general Yuwen Huaji. Li Yuan made Emperor Gong yield the throne to him, establishing Tang Dynasty and declaring himself Emperor Gaozu. He created Li Jiancheng Crown Prince, but made Li Shimin the Prince of Qin, also appointing him Shangshu Ling (尚書令), the head of the executive bureau of the government (尚書省, Shangshu Sheng), a post similar to that of a chancellor. At the same time, Li Shimin continued to serve as a major general.

During Emperor Gaozu's Reign

The campaign to reunify the empire

Xue Ju attacked Jing Prefecture (涇州, roughly modern Pingliang, Gansu) and Emperor Gaozu sent Li Shimin to resist him. Li Shimin established his defenses and refused to engage Xue, intending to wear down Xue Ju’s forces. However, Li Shimin became ill with malaria and let his assistants Liu Wenjing and Yin Kaishan (殷開山) take command, ordering them not to engage Xue Ju. Liu and Yin did not take the threat of Xue Ju seriously, and Xue Ju ambushed them at Qianshui Plain (淺水原, in modern Xianyang), crushing the Tang forces and killing more than half of the troops. Li Shimin was forced to withdraw to Chang'an, and Liu and Yin were removed from their posts. This was the only defeat of Li Shimin documented in historical records until the Goguryeo campaign of 645.

The victorious Xue Ju was prepared to launch an assault on Chang'an itself, at the advice of Hao Yuan, but died suddenly of an illness in the fall of 618 and was succeeded by Xue Rengao. Emperor Gaozu then sent Li Shimin against Xue Rengao. Three months after Xue Rengao took the throne, after a fierce battle between Li Shimin and Xue Rengao's major general Zong Luohou (宗羅睺), Zong's forces were crushed. Xue Rengao withdrew into the city of Gaozhi (高墌, in modern Xianyang), and his soldiers began surrendering to Li Shimin in mass. Xue Rengao was forced to surrender, and Li Shimin had him delivered to Chang'an, where he was executed. Around the New Year in 619, Emperor Gaozu made Li Shimin Taiwei (太尉, one of the Three Excellencies) and put him in charge of Tang operations east of the Tong Pass.

In spring 619, Liu Wuzhou launched a major offensive against Tang. He captured Taiyuan in summer 619, forcing Li Yuanji, who had been in charge there, to flee, and then continued his offensive south. Emperor Gaozu sent Pei Ji against him, but by the winter of 619, Liu had crushed Pei's forces and taken over nearly all of modern Shanxi. Emperor Gaozu considered abandoning the region altogether. Li Shimin offered to lead an army against Liu, and Emperor Gaozu agreed and commissioned him with an army. Li Shimin crossed the Yellow River and approached Liu's major general Song Jin'gang (宋金剛) but did not engage him, choosing to try to wear Song out. He had his subordinates Yin Kaishan and Qin Shubao engage the other Dingyang generals Yuchi Jingde and Xun Xiang (尋相) in relatively low-level engagements. Eventually, in the spring 620, when Liu and Song ran out of food supplies, they retreated, and Li Shimin gave chase, dealing Song a major defeat. Yuchi and Xun surrendered, and Li Shimin pursued Liu and Song until they fled to Eastern Tujue. All of Dingyang territory fell into Tang hands.

In the summer of 620, Emperor Gaozu again commissioned Li Shimin against a major enemy, the former Sui general Wang Shichong, who had made Sui's last emperor, Emperor Yang's grandson Yang Tong, yield the throne to him in 619, establishing a new state of Zheng as its emperor. When Li Shimin arrived at the Zheng capital Luoyang, Wang offered peace, but Li Shimin rebuffed him and put Luoyang under siege, while his subordinates took Zheng cities one by one. By the winter of 620, most of Zheng territory, except for Luoyang and Xiangyang (襄陽, in modern Xiangfan, Hubei), defended by Wang Shichong's nephew Wang Honglie (王弘烈), had submitted to Tang. Wang sought the assistance of Dou Jiande the Prince of Xia, who controlled most of modern Hebei. Dou, reasoning that if Tang were able to destroy Zheng, his own Xia state would be threatened, agreed. He sent an official, Li Dashi, to try to persuade Li Shimin to withdraw, but Li Shimin detained Li Dashi and gave no response. Li Shimin chose some 1000 elite soldiers, clad in black uniform and black armor, commanded by himself, to serve as advance forward troops, with Qin, Cheng Zhijie (程知節), Yuchi, and Zhai Zhangsun (翟長孫) as his assistants.

Battle of Hulao

By the spring of 621, Luoyang was in a desperate situation, and Xia forces had not yet arrived. Luoyang's defenses, aided by powerful bows and catapults, had inflicted serious casualties on the Tang troops. Emperor Gaozu, hearing that Dou had decided to come to Wang's aid, ordered Li Shimin to withdraw, but Li Shimin sent his secretary Feng Deyi to Chang'an to explain to Emperor Gaozu that if he did withdraw, Wang would recover and again be a major threat in the future. Emperor Gaozu agreed and allowed Li Shimin to continue the siege of Luoyang. When the Xia forward troops arrived, Li Shimin surprised and defeated them, and then sent Dou a letter suggesting that he withdraw. Dou refused, and, against the advice of his wife Empress Cao and secretary general Ling Jing (凌敬) that he should instead attack Tang's prefectures in modern southern Shanxi, he marched toward Luoyang.

Anticipating Dou's maneuver, Li Shimin left a small detachment, commanded by Li Yuanji, at Luoyang, while marching east himself, taking up positions at the strategic Hulao Pass. When the armies engaged at Hulao, Li Shimin defeated Dou and captured him. He took Dou back to Luoyang and displayed him to Wang Shichong. Wang, in fear, considered abandoning Luoyang and fleeing south to Xiangyang, but reminded by his generals that Dou had been his only hope, he surrendered. Xia forces, after initially fleeing to the Xia capital in Ming Prefecture (洺州, in modern Handan, Hebei), also surrendered. Zheng and Xia territory were now under Tang control. Li Shimin returned to Chang'an in a grand victory procession, and, as a reward, Emperor Gaozu awarded both him and Li Yuanji three mints so that they could mint money of their own. He also bestowed on Li Shimin the special title of "Grand General of Heavenly Strategies" (天策上將, Tiance Shangjiang). Meanwhile, Li Shimin's staff of generals and strategists, was being supplemented with a number of literary men.

The former Xia territory did not remain in Tang hands for long, as in winter 621, the Xia general Liu Heita rose against Tang rule, claiming to avenge Dou, whom Emperor Gaozu had executed in Chang'an. Liu was allied with Xu Yuanlang, a former agrarian rebel general who was nominally under Wang Shichong and who had submitted to Tang after Wang's defeat. Liu dealt successive defeats to Emperor Gaozu's cousin Li Shentong (李神通) the Prince of Huai'an, Li Xiaochang (李孝常) the Prince of Yi'an, and Li Shiji. Emperor Gaozu sent Li Shimin and Li Yuanji against Liu. In 622, after some indecisive battles with Liu, who had by then taken over almost all of former Xia territory and claimed the title of Prince of Handong, Li Shimin defeated Liu by flooding his army with water from the Ming River (洺水, flowing near Ming Prefecture), and Liu fled to Eastern Tujue. Li Shimin then headed east and attacked Xu, defeating him. After leaving Li Shiji, Li Shentong, and Ren Gui (任瓌) to continue the attack on Xu, Li Shimin returned to Chang'an.

The struggle against Li Jiancheng and Li Yuanji

An intense rivalry arose between Li Shimin and his older brother Li Jiancheng, who had been created Crown Prince in 618, reportedly after Emperor Gaozu first offered the position to Li Shimin as a reward for his contributions. Li Shimin's accomplishments caused people to speculate that he might displace Li Jiancheng as Crown Prince, and Li Jiancheng, an accomplished general himself, was overshadowed by his younger brother. The court became divided into a faction favoring the Crown Prince and a faction favoring the Prince of Qin. The rivalry caused particular problems within capital, because the commands of the Crown Prince, the Prince of Qin, and the Prince of Qi (Li Yuanji) were considered to have the same force as the emperor's edicts, and officials had to carry out conflicting orders, usually acting on the ones that arrived first. Li Shimin had a staff of talented men, but Li Jiancheng was supported by Li Yuanji, as well as Emperor Gaozu's concubines, who had better relationships with Li Jiancheng and Li Yuanji than they did with Li Shimin.

Late in 622, when Liu Heita returned to former Xia domain after receiving aid from Eastern Tujue, defeating and killing Li Shimin's cousin Li Daoxuan (李道玄) the Prince of Huaiyang, he again regained most of former Xia territory. Li Jiancheng's staff members Wang Gui and Wei Zheng suggested that Li Jiancheng needed to enhance his own reputation in battle, and so Li Jiancheng volunteered to march against Liu. Emperor Gaozu sent Li Jiancheng, assisted by Li Yuanji, to attack Liu. Li Jiancheng defeated Liu around the New Year in 623, and Liu was betrayed by his own official Zhuge Dewei (諸葛德威) and delivered to Li Jiancheng. Li Jiancheng killed Liu and returned to Chang'an in triumph. This victory roughly united China under Tang rule.

For the next few years, the rivalry between Li Jiancheng and Li Shimin intensified, although both served as generals when Eastern Tujue made incursions. In 623, when the general Fu Gongshi rebelled at Danyang (丹楊, in modern Nanjing, Jiangsu), Emperor Gaozu briefly commissioned Li Shimin to attack Fu, but soon cancelled the order and sent Li Shimin's cousin Li Xiaogong, the Prince of Zhao Commandery, instead.

In 624, when Li Jiancheng was found to have, against regulations, tried to add soldiers to his guard corps, Emperor Gaozu was so angry that he put Li Jiancheng under arrest. In fear, Li Jiancheng's guard commander Yang Wen'gan (楊文幹) rebelled. Emperor Gaozu sent Li Shimin against Yang, offering to make him Crown Prince on his return. After Li Shimin left, however, Feng Deyi (now a chancellor), Li Yuanji, and the concubines all spoke on Li Jiancheng's behalf, and after Li Shimin returned, Emperor Gaozu did not depose Li Jiancheng. Instead, he blamed the discord between him and Li Shimin on Li Jiancheng's staff members Wang Gui and Wei Ting (韋挺) and Li Shimin's staff member Du Yan, exiling them to Xi Prefecture (巂州, roughly modern Liangshan Yi Autonomous Prefecture, Sichuan).

Later that year, Emperor Gaozu, troubled by repeated Eastern Tujue incursions, seriously considered burning Chang'an to the ground and moving the capital to Fancheng (樊城, also in modern Xiangfan), a suggestion that Li Jiancheng, Li Yuanji, and Pei Ji agreed with. Li Shimin opposed the plan, however, and it was not carried out. Meanwhile, Li Shimin was sending his confidants to Luoyang to build up personal control of the army there. After an incident in which Li Shimin suffered a severe case of food poisoning after feasting at Li Jiancheng's palace, an event that both Emperor Gaozu and Li Shimin apparently interpreted as an assassination attempt, Emperor Gaozu considered sending Li Shimin to guard Luoyang to prevent further conflict. Li Jiancheng and Li Yuanji opposed this plan because they believed that it would only give Li Shimin an opportunity to build up his personal influence in Luoyang, so Emperor Gaozu did not carry it out.

The rivalry continued. According to traditional historical accounts, in one incident, when Li Shimin visited Li Yuanji's mansion, Li Yuanji wanted to assassinate him, but Li Jiancheng, who could not resolve to kill a brother, stopped the plot. There was another incident in which Li Jiancheng deliberately had Li Shimin ride a horse that was known for throwing its riders, causing him to fall off it several times.

By 626, Li Shimin was fearful that he would be killed by Li Jiancheng. His staff members Fang Xuanling, Du Ruhui, and Zhangsun Wuji repeatedly encouraged Li Shimin to attack Li Jiancheng and Li Yuanji first, while Wei Zheng was encouraged Li Jiancheng to attack Li Shimin first. Li Jiancheng persuaded Emperor Gaozu to remove Fang and Du, as well as Li Shimin's trusted guard officers Yuchi Jingde and Cheng Zhijie, from Li Shimin's staff. Zhangsun, who remained on Li Shimin's staff, continued to try to persuade Li Shimin to attack first.

In the summer of 626, Eastern Tujue was making another attack. At Li Jiancheng's suggestion, Emperor Gaozu, instead of sending Li Shimin to resist Eastern Tujue as he had first intended, decided to send Li Yuanji instead. Li Yuanji was given command of much of the army previously under Li Shimin's control, further troubling Li Shimin, who believed that with the army under Li Yuanji's control, he would be unable to resist an attack. Li Shimin had Yuchi secretly summoned Fang and Du back to his mansion. One night, he submitted an accusation to Emperor Gaozu that Li Jiancheng and Li Yuanji were committing adultery with Emperor Gaozu's concubines. In response, Emperor Gaozu, issued summonses to Li Jiancheng and Li Yuanji to come to his palace the next morning, where the senior officials Pei Ji, Xiao Yu, and Chen Shuda would convene to examine Li Shimin's accusations. As Li Jiancheng and Li Yuanji approached the central gate leading to Emperor Gaozu's palace, Xuanwu Gate (玄武門), Li Shimin ambushed them. He personally fired an arrow that killed Li Jiancheng. Yuchi killed Li Yuanji. Li Shimin's forces entered the palace and intimidated Emperor Gaozu into creating Li Shimin crown prince. The sons of Li Jiancheng and Li Yuanji were killed, and Li Shimin took Li Yuanji's wife Princess Yang as a concubine. Two months later, Emperor Gaozu yielded the throne to Li Shimin as Emperor Taizong.

Early Reign

One of the first actions that Emperor Taizong carried out as emperor was releasing a number of ladies in waiting from the palace and returning them to their homes, so that they could be married. He created his wife Princess Zhangsun as empress, and their oldest son Li Chengqian as crown prince.

Emperor Taizong faced a crisis almost immediately, as Eastern Tujue's Jiali Khan Ashina Duobi, along with his nephew the subordinate Tuli Khan Ashina Shibobi (阿史那什鉢苾), launched a major incursion toward Chang'an. Just 19 days after Emperor Taizong took the throne, the two khans were across the Wei River from Chang'an. Emperor Taizong, accompanied by Gao Shilian and Fang Xuanling, was obliged to meet Ashina Duobi across the river and personally negotiate peace terms, including tributes to Eastern Tujue, before Ashina Duobi withdrew.

Late in 626, Emperor Taizong ranked the contributors to Tang rule and granted them titles and fiefs, naming among the first rank of contributors Zhangsun Wuji, Fang, Du Ruhui, Yuchi Jingde, and Hou Junji. When Li Shentong, his distant uncle, objected to being ranked under Fang and Du, Emperor Taizong personally explained how Fang and Du's strategies had allowed him to be successful. This example pacified the others who were objecting to being assigned lower ranks. Emperor Taizong also buried Li Jiancheng and Li Yuanji with the honors due imperial princes and had their staff members attend the funeral processions.

Taizong began to reorganize the government, dismissing his father's trusted advisors Xiao Yu and Chen Shuda, and making his own trusted advisors chancellors. Xiao was soon restored as chancellor, but his career during Emperor Taizong's reign was one of repeated dismissals and restorations. However, he also began to pay careful attention to the officials' submissions and their criticisms of imperial governance, making changes where he saw the need. He also began to trust Wei Zheng in particular, accepting much advice from Wei concerning his personal conduct. He was also willing to demote his own trusted advisors, as he demoted Gao after finding that Gao had held back submissions from his deputy Wang Gui. Viewing Sui's Emperor Yang as a negative example, he frequently solicited criticisms, rewarding those officials, such as Wei and Wang Gui, who were willing to offer them.

In 627, the general Li Yi, Prince of Yan, a late-Sui warlord who later submitted to Tang and had been associated with Li Jiancheng, fearing that Emperor Taizong would eventually take action against him, rebelled in Bin Prefecture (豳州, in modern Xianyang), but was quickly crushed by the official Yang Ji (楊岌) and killed in flight. Later that year, when Emperor Gaozu's cousin Li Youliang (李幼良) the Prince of Changle, the commandant at Liang Prefecture (涼州, roughly modern Wuwei, Gansu), was accused of allowing his staff to oppress the people and to trade with Qiang and Xiongnu tribesmen, Emperor Taizong sent the chancellor Yuwen Shiji (Yuwen Huaji's brother) to investigate. Fearing for their lives, Li Youliang's staff members plotted to hold him hostage and rebel. When this was discovered, Emperor Taizong forced Li Youliang to commit suicide. Late in the year, Wang Junkuo (王君廓), the commandant at You Prefecture (幽州, roughly modern Beijing), also rebelled, but was defeated quickly and killed in flight. When there were reports that Feng Ang (馮盎), a warlord in the modern Guangdong region, was rebelling, Emperor Taizong, at Wei's suggestion, sent messengers to appease Feng, and Feng submitted.

Also in 627, Emperor Taizong, seeing that there were too many prefectures and counties, consolidated and merged many of them, and created another level of local political organization above prefectures—the circuit (道, dao)—dividing his state into ten circuits.

In 628, Ashina Duobi and Ashina Shibobi had a falling out, and Ashina Shibobi submitted to Emperor Taizong, as did the chieftains of Khitan tribes, who had previously submitted to Eastern Tujue. With Eastern Tujue in turmoil, Ashina Duobi was no longer able to protect the last late-Sui rebel ruler who alone remained standing against Tang pressure, Liang Shidu, the Emperor of Liang. In the summer of 628, with the Tang generals Chai Shao and Xue Wanjun (薛萬均) besieging the Liang capital Shuofang (朔方, in modern Yulin, Shaanxi), Liang Shidu's cousin Liang Luoren (梁洛仁) killed Liang Shidu and surrendered, finally uniting China. Eastern Tujue's vassal Xueyantuo broke away from the weakened Eastern Tujue and formed its own khanate, and Emperor Taizong entered into an alliance with Xueyantuo's leader Yi'nan (夷男), creating Yi'nan the Zhenzhupiqie Khan (真珠毗伽可汗, or Zhenzhu Khan).

In late 629, believing the time ripe for a major attack on Eastern Tujue, Emperor Taizong commissioned the general Li Jing with overall command of a multi-pronged army, assisted by the generals Li Shiji, Chai, and Xue Wanche (薛萬徹, Xue Wanjun's brother), to attack Eastern Tujue at multiple points. The army was successful in its attacks, forcing Ashina Duobi to flee, and by late spring of 630, Ashina Duobi had been captured, and Eastern Tujue chieftains had all submitted to Tang. Emperor Taizong spared Ashina Duobi but detained him at Chang'an, as he considered what to do with the Eastern Tujue people. Chancellor Wen Yanbo advocated leaving the Eastern Tujue people within Chinese borders to serve as a defense perimeter, and Chancellor Wei advocated leaving them outside the borders. Emperor Taizong accepted Wen's suggestion and established a number of prefectures to accommodate the Eastern Tujue people, still leaving them governed by their chieftains, without creating a new khan to govern them.

In 631, Emperor Taizong established a feudal scheme, where the contributors to his reign were given, in addition to their current posts, additional posts as prefectural governors, to be passed on to their descendants. This scheme was soon cancelled, however, because of strong opposition from his advisers, particularly from Zhangsun Wuji.

After the conquest of Eastern Tujue, Emperor Taizong's officials repeatedly requested that he carry out sacrifices to heaven and earth at Mount Tai. Emperor Taizong, though tempted by the proposal, was repeatedly dissuaded from doing so by Wei, who pointed out that such an endeavor would impose heavy expenses and labor burdens on the people, and open China's borders to possible attack.

Middle reign

In 634, Emperor Taizong sent thirteen high level officials, including Li Jing and Xiao Yu, to examine the circuits to see whether the local officials were capable, to find out whether the people were suffering, to comfort the poor, and to select capable people to serve in civil service. Li Jing initially recommended that Wei accompany them on the examination, but Emperor Taizong declared that Wei needed to stay to point out his faults, and that he could not afford to have Wei away even for a single day.

Around this time, conflicts were increasing between Tang and Tuyuhun, whose Busabo Khan Murong Fuyun, following the advice of his strategist, the Prince of Tianzhu, had been repeatedly attacking the borders of Tang prefectures. At one point, Murong Fuyun sought to have a Tang princess marry his son Murong Zunwang (慕容尊王), but the marriage negotiations broke down over Emperor Taizong's insistence that Murong Zunwang come to Chang'an for the wedding. In the summer of 634, Emperor Taizong sent generals Duan Zhixuan and Fan Xing (樊興) to lead forces against Tuyuhun, but Duan, while not defeated, could not make major gains against Tuyuhun's highly mobile forces, who avoided direct confrontation. Once Duan withdrew, Tuyuhun resumed hostilities. In winter 634, the Tufan king Songtsän Gampo also made overtures to marry a Tang princess, and Emperor Taizong sent the emissary Feng Dexia (馮德遐) to Tufan to negotiate an alliance against Tuyuhun. In the winter of 634, he commissioned Li Jing, assisted by the other generals Hou Junji, Li Daozong, Li Daliang (李大亮), Li Daoyan (李道彥), and Gao Zengsheng (高甑生), to attack Tuyuhun. In 635, Li Jing's forces crushed the Tuyuhun forces. Murong Fuyun was killed by his own subordinates, and his son Murong Shun killed the Prince of Tianzhu and surrendered. Emperor Taizong created Murong Shun the new khan, and when he was assassinated soon afterward, made Murong Shun's son Murong Nuohebo khan in his place

Also in 635, Emperor Gaozu died, and Emperor Taizong briefly had Li Chengqian serve as regent while he observed a mourning period. When he resumed his authority less than two months later, he continued to authorize Li Chengqian to rule on minor matters.

In the spring of 636, Emperor Taizong commissioned his brothers and sons as commandants and changed their titles in accordance with the commands that they received. He sent them to their posts with the exception of his son Li Tai, Prince of Wei, who by this point was beginning to be highly favored by him. He allowed Li Tai, who favored literature, to engage literary men as assistants. Rumors began to circulate that Emperor Taizong might let Li Tai displace Li Chengqian, his eldest son, who was beginning to lose favor.

In the fall of 636, Empress Zhangsun died. Emperor Taizong mourned her bitterly and personally wrote the text of her monument.

In the summer of 637, Emperor Taizong attempted to establish the feudal scheme that he had considered and abandoned in 631, creating 35 hereditary prefect posts. By 639, however, the system was again abandoned in the face of much opposition.

Sometime before 638, Emperor Taizong, disgusted with the traditional noble clans of Cui, Lu, Li, and Zheng and believing that they were abusing their highly honored names, commissioned Gao Shilian, Wei Ting, Linghu Defen (令狐德棻), and Cen Wenben to compile a work, later known as the Records of Clans (氏族志). It was intended to divide the clans into nine classes based on their past contributions, and good and bad deeds. Gao submitted an initial draft in which he ranked the branch of the Cui clan of the official Cui Min'gan (崔民幹) as the highest, a decision that Emperor Taizong rejected, pointing out that Gao was looking at tradition and not at recent contributions. Taizong personally intervened in the revision of the work, reducing Cui's clan to the third class.

In the fall 638, Tufan's Songtsän Gampo, displeased because Emperor Taizong had declined to give him a Tang princess in marriage, and believing that Murong Nuohebo had persuaded Emperor Taizong to decline the marriage proposal, launched a major attack with a force of 200,000 on Tuyuhun and then on several Tang prefectures, putting Song Prefecture (松州, roughly modern Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan) under siege. Emperor Taizong commissioned Hou, assisted by Zhishi Sili (執失思力), Niu Jinda (牛進達), and Liu Jian (劉簡), with a total of force of 50,000, to counterattack, and Niu, who commanded the forward forces, defeated the Tufan forces at Song Prefecture. Songsän Gampo withdrew and sued for peace, still requesting a Tang princess in marriage. Emperor Taizong agreed this time.

Also in 638, believing that Xueyantuo was growing increasingly strong and difficult to control, Emperor Taizong granted Yi'nan's sons Bazhuo and Jialibi (頡利苾) both lesser khan titles, to try to create dissension between them.

In the summer of 639, Ashian Jiesheshuai (阿史那結社率), the younger brother of Ashina Shibobi, to whom Emperor Taizong gave little recognition, formed a conspiracy with Ashina Shibobi's son Ashina Hexiangu (阿史那賀暹鶻) to assassinate Emperor Taizong. They planned to wait for Li Zhi, the Prince of Jin, to depart from the palace in the morning and use that opportunity to attack the palace. On the day they planned to attack, however, Li Zhi did not leave the palace. Ashina Jiesheshuai attacked anyway, but was quickly defeated, captured, and executed. After this incident, however, the officials advocated sending the Tujue people away from the heart of the state. In the fall of 639, Emperor Taizong created a Tujue prince who had served him faithfully, Li Simo (李思摩, né Ashina Simo) as the khan of a newly constituted Eastern Tujue state (as Qilibi Khan), giving him all of the Tujue and Xiongnu who had surrendered as his subordinates, to be settled north of the Great Wall and the Yellow River. However, the Tujue people were fearful of Xueyantuo and initially refused to go to their new location. Emperor Taizong issued an edict to Yi'nan ordering him to keep peace with Li Simo and not attack his people. After receiving an assurance from Yi'nan that he would not attack, the Tujue people advanced to the new location.

Meanwhile, Qu Wentai (麴文泰), the king of Gaochang, who had previously been submissive, had become increasingly hostile to Tang, allying with Western Tujue. In 640, Emperor Taizong commissioned Hou, assisted by Xue Wanjun, to launch a major attack on Gaochang. As they approached Gaochang, Qu Wentai died of fear and was succeeded by his son Qu Zhisheng (麴智盛). Qu Zhisheng offered to submit, but Hou demanded a surrender, which Qu Zhisheng refused. Hou put Gaochang under siege, and when aid from Western Tujue did not arrive, Qu Zhisheng surrendered. Wei suggested that Emperor Taizong allow Qu Zhisheng to remain king, pointing out the high monetary and human costs involved in maintaining a permanent garrison at Gaochang. Emperor Taizong disagreed, and converted Gaochang into two prefectures which he annexed to his state.

In the winter of 640, Songsän Gampo sent his prime minister Ludongzan (祿東贊) as an emissary to Tang, offering tributes and again requesting marriage. Emperor Taizong created a daughter of a clansman as the Princess Wencheng, and in 641 sent Li Daozong to accompany Princess Wencheng to Tufan and preside over the wedding.

In the winter of 641, believing that Emperor Taizong was about to carry out sacrifices to heaven and earth at Mount Tai and would be unable to aid Eastern Tujue, Yi'nan launched a major attack on Eastern Tujue, commanded by his son Dadu (大度). Li Simo was forced to retreat inside the Great Wall. Emperor Taizong commissioned Li Shiji, assisted by Zhang Jian (張儉), Li Daliang, Zhang Shigui (張士貴), and Li Xiyu (李襲譽), to attack Xueyantuo. Li Shiji soon defeated Dadu at Nuozhen River (諾真水, flowing through modern Baotou, Inner Mongolia), and routed him.

Late Reign

In 642, it was clear that Li Tai had ambitions to replace his brother Li Chengqian as Crown Prince, and the governmental officials devolved into pro-Li Chengqian and pro-Li Tai factions. Wei Zheng and Chu Suiliang urged Emperor Taizong to take action and clarify that Li Chengqian's position was secure. Taizong attempted to do this by making repeated statements that he supported Li Chengqian as Crown Prince, but his obvious preference for Li Tai led to continued speculation among officials.

By 642, Xueyantuo, though still formally submissive, posed a sufficiently serious threat that Emperor Taizong saw only two alternatives: destroy it by force, or form a heqin relationship by marrying one of his daughters to Yi'nan. The situation was aggravated when the Tang general Qibi Heli (契苾何力), chieftain of the Qibi Tribe, was kidnapped by his own subordinates and taken to Xueyantuo. In order to ransom Qibi, Emperor Taizong made a promise to eventually give his daughter Princess Xinxing to Yi'nan in marriage, and Yi'nan released Qibi.

In the winter of 642, an event took place in Goguryeo that would eventually precipitate wars between Tang and Goguryeo. According to Chinese accounts^[6] Gao Jianwu (Go Geonmu; King Yeongnyu), the king of Goguryeo, was apprehensive about his general Yeon Gaesomun and was plotting with his other officials to kill Yeon. When Yeon heard this, he began a coup and killed the king and the high level officials. He declared King Yeongnyu's nephew Gao Zang (Go Jang; King Bojang) king, while taking power himself with the title of Mangniji (莫離支/막리지, regent). When Emperor Taizong received this news, some of his advisers suggested that an attack be launched against Goguryeo, but he initially declined.

In the spring of 643, Wei died. Emperor Taizong mourned him bitterly, authoring Wei's monument himself. Prior to Wei's death, he promised to give his daughter, Princess Hengshan, in marriage to Wei's son Wei Shuyu (魏叔玉). Later in the spring, Emperor Taizong commissioned 24 portraits at Lingyan Pavilion to commemorate the 24 great contributors to his reign.

Also during 643, turmoil arose among Emperor Taizong’s closest family members. In the spring of 643, his son Li You (李祐), the Prince of Qi, angry over the restrictions that Taizong’s secretary general Quan Wanji (權萬紀) had often placed on him, killed Quan and declared a rebellion. Emperor Taizong sent Li Shiji against Li You, but before Li Shiji could engage him, Li You was captured by his own subordinate Du Xingmin (杜行敏) and delivered to Chang'an, where Emperor Taizong ordered him to commit suicide and executed 44 of his associates.

The death of Li You exposed another plot. Li Chengqian, fearful that Emperor Taizong would eventually remove him as Crown Prince and replace him with Li Tai, had begun to conspire with Hou Junji, Li Yuanchang (李元昌) the Prince of Han (Emperor Taizong's brother), the general Li Anyan (李安儼), and his brothers-in-law Zhao Jie (趙節) and Du He (杜荷, Du Ruhui's son) to overthrow Emperor Taizong. During the investigations in the aftermath of Li You's rebellion, one of the co-conspirators, Li Chengqian's guard Gegan Chengji (紇干承基), was implicated by association, and in order to save himself, he revealed Li Chengqian's plot. Emperor Taizong, shocked, appointed Zhangsun Wuji, Fang Xuanling, Xiao Yu, and Li Shiji, along with the officials in charge of the supreme court and the legislative and examination bureaus of the government, to carry out a joint investigation. At the suggestion of the mid-level official Lai Ji, Emperor Taizong deposed, but did not kill, Li Chengqian, ordered Li Yuanchang to commit suicide, and executed Hou, Li Anyan, Zhao, and Du.

After Li Chenqian was deposed, Emperor Taizong briefly promised Li Tai that he would be made Crown Prince. However, as the investigations continued, Emperor Taizong came to believe that Li Chengqian's downfall was driven by Li Tai's machinations, and resolved to depose Li Tai as well. At Zhangsun's suggestion, Emperor Taizong created a younger son by Empress Zhangsun, Li Zhi, who was considered kinder and gentler, the Prince of Jin, and exiled Li Chengqian and Li Tai.

Coming to the conclusion that his promise to give his daughter, Princess Xinxing, in marriage to Yi'nan, had been ill-advised, Emperor Taizong demanded a large bride price of 50,000 horses, 10,000 cows and camels, and 100,000 sheep. Yi'nan agreed to this price, but could not immediately collect and deliver it. Emperor Taizong used this as an excuse to cancel the marriage agreement.

Wei Zheng had, prior to his death, recommended Hou and Li Chengqian's staff member Du Zhenglun as chancellors. Emperor Taizong came to suspect that Wei was part of the plot to overthrow him. He destroyed the monument he had authored for Wei, and cancelled the betrothal between Wei Shuyu and Princess Hengshan.

In 644, Yanqi's king Long Tuqizhi (龍突騎支), who had assisted in the Tang campaign to conquer Gaochang, turned against Tang and allied with Western Tujue. Emperor Taizong sent the general Guo Xiaoke (郭孝恪), the commandant at Anxi (安西 ; Gaochang), to launch a surprise attack on Yanqi. Guo caught Long Tuqizhi by surprise and captured him, making his brother Long Lipozhun (龍栗婆準) regent. (The Western Tujue viceroy Ashina Quli (阿史那屈利) subsequently captured Long Lipozhun and briefly occupied Yanqi; not wanting a direct confrontation with Tang, he then withdrew, and the Yanqi nobles made Long Tuqizhi's cousin Long Xuepoanazhi (龍薛婆阿那支) king.)

In 644, Goguryeo attacked Silla and Silla requesting aid. Emperor Taizong decided to prepare for a campaign to conquer Goguryeo. He arrested the emissaries that Yeon sent to the Tang court, accusing them of disloyalty to King Yeongnyu. By the winter of 644, the mobilization was in full force. Apparently, Tang's preparations to attack Goguryeo caused the reconstituted Eastern Tujue people to fear that Xueyantuo would attack them while the Tang were ill-equipped to assist. They panicked and abandoned their khan Li Simo, fleeing into Tang territory. Emperor Taizong reabsorbed the Eastern Tujue people into Tang, and made Li Simo a general in his army.

In the spring of 645, Emperor Taizong departed from Luoyang and led the troops northeast, behind 60,000 forward forces commanded by Li Shiji and Li Daozong. At the same time, Zhang Liang led another 40,000 from the sea. By the summer of 645, Tang forces had captured Liaodong (遼東, in modern Liaoyang, Liaoning), and headed southeast toward the Goguryeo capital Pyongyang. Emperor Taizong's force of 20,000 (11,000 commanded by Zhangsun Wuji, 4000 infantry/cavalry by Taizong, and 5000 cavalry by Shiji) defeated a large force of 150,000 commanded by the Goguryeo generals Gao Yanshou (高延壽) and Gao Huizhen (高惠真) and then put Anshi (安市, in modern Anshan, Liaoning) under siege. However, the capable defense put up by Anshi's commanding general (whose name is not recorded in history but traditionally is believed to be Yang Manchun) blocked the Tang forces and, in late fall, with winter fast approaching and his food supplies running out, Emperor Taizong withdrew. He much regretted launching the campaign and made the comment, "If Wei Zheng were still alive, he would never have let me launch this campaign." He re-erected the monument he had authored for Wei and summoned Wei's wife and children to meet him, treating them well. He also began to suffer from an illness or injury, which might have been inflicted during the Gogureyo campaign, from which he apparently never completely recovered from.

In the aftermath of the Goguryeo campaign, Xueyantuo's Duomi Khan Bazhuo (拔灼, son of Yi'nan, who had died earlier in 645) launched attacks against Tang's border prefectures, with largely inconclusive results. In the spring of 646, the Tang generals Qiao Shiwang (喬師望) and Zhishi Sili counterattacked, defeating Bazhuo's forces, and causing him to flee. His vassals, the Huige, Pugu (僕骨), and Tongluo (同羅) tribes took this opportunity to rebel and attack him. Hearing this, Emperor Taizong launched a major attack, commanded by Li Daozong, Ashina She'er (阿史那社爾), Zhishi, Qibi, Xue Wanche, and Zhang Jian, against Xueyantuo. With Xueyantuo under attack from multiple sides, Bazhuo was killed by Huige forces. The remaining Xueyantuo people fled and supported Bazhuo's cousin Duomozhi (咄摩支) as Yitewushi Khan, but soon offered to submit to Tang. Emperor Taizong sent Li Shiji toward Duomozhi's location, with the direction to either accept his submission or destroy him. Duomozhi surrendered and was taken to Chang'an, ending Xueyantuo's rule over the region. The other tribes formerly submissive to Xueyantuo offered Emperor Taizong the title of "Heavenly Khan" and thereafter largely became submissive to Tang. Tang nominally established seven command posts and six prefectures over the region. (Huige's khan Yaoluoge Tumidu (藥羅葛吐迷度), while submissive to Tang, for some time tried to take control over the region himself, but was assassinated in 648, and there was no other organized attempt by Huige to take over the region for another century.)

After the victory over Xueyantuo, Emperor Taizong again turned his attention to Goguryeo, cutting off relations once more and considering another campaign. SHis officials advised him to weaken Goguryeo gradually by conducting annual harassment campaigns against Goguryeo's northern region. The first of these campaigns was launched in the spring of 647, with Niu Jinda and Li Shiji in command, and the attacks were repeated in preparation for another campaign in 649 with forces totaling 300,000, which took place after Taizong died, during Gaozong's reign.

In 648, Emperor Taizong launched another campaign, commanded by Ashina She'er, aimed at Qiuzi (龜玆, in modern Akesu Prefecture, Xinjiang]). Ashina She'er first attacked Yanqi, killed Long Xuepoanazhi, and replaced him with his cousin Long Xiannazhun (龍先那準). Ashina She'er then advanced on Qiuzi and captured its king Bai Helibushibi (白訶黎布失畢), making his brother king instead.

Death

By the summer of 649, Emperor Taizong was seriously ill; some suspected that his illness was caused by ingesting pills given him by alchemists. Believing Li Shiji to be capable but fearing that he would not be submissive to Li Zhi, he demoted Li Shiji out of the capital and made him commandant in the remote Die Prefecture (疊州, roughly modern Gannan Tibetan Autonomous Prefecture, Gansu). Taizong gave instructions to Li Zhi to have Li Shiji executed immediately if he hesitated, and if he did not, to recall him after Emperor Taizong's death and make him chancellor. When Li Shiji received the order, he realized that his life was at stake and immediately departed for Die Prefecture. (After Emperor Taizong's death, Li Zhi did recall Li Shiji and make him chancellor.) Soon afterward, Emperor Taizong, after entrusting Li Zhi to Zhangsun Wuji and Chu, died at his summer palace, Cuiwei Palace (翠微宮). His death was initially kept a secret, and not announced until three days later, after his casket had been returned to Chang'an. Li Zhi took the throne as Emperor Gaozong.

"A country cannot be a country without people and a ruler cannot be a ruler without a country. When the ruler looks as firm and lofty as a mountain peak and as pure, bright, and illuminating as the sun and the moon, the people will admire and respect him. He must broaden his will so as to be able to embrace both Heaven and earth and must regulate his heart so as to be able to make just decisions. He cannot expand his territory without majesty and virtue; he cannot soothe and protect his people without compassion and kindness. He comforts his relations with benevolence, treats his officials with courtesy, honors his ancestors with filial respect, and receives his subordinates with thoughtfulness. Having disciplined himself, he practices virtue and righteousness diligently. This is how a ruler should act." -Taizong of Tang, How A Ruler Should Act, Di Fan

Era name

• Zhen'guan (貞觀 zhēn guān) 627-649

Chancellors during reign

• Xiao Yu (626, 627, 630, 643-646)
• Chen Shuda (626)
• Feng Deyi (626-627)
• Yuwen Shiji (626-627)
• Gao Shilian (626-627, 638-647)
• Fang Xuanling (626-643, 643-648)
• Zhangsun Wuji (627-628, 645-649)
• Du Yan (627-628)
• Du Ruhui (628-629)
• Li Jing (628-634)
• Wang Gui (628-633)
• Wei Zheng (629-642)
• Wen Yanbo (630-637)
• Dai Zhou (630-633)
• Hou Junji (630-632, 632-643)
• Yang Shidao (636-643, 645)
• Liu Ji (639-645)
• Cen Wenben (642-645)
• Li Shiji (643-649)
• Zhang Liang (643-646)
• Ma Zhou (644-648)
• Chu Suiliang (644-647, 648-649)
• Xu Jingzong (645)^[7]
• Gao Jifu (645)^[7]
• Zhang Xingcheng (645)^[7]
• Cui Renshi (648)

Family

• Father
  • Emperor Gaozu of Tang
• Mother
  • Duchess Dou, Emperor Gaozu's wife, daughter of Dou Yi (竇毅) the Duke of Shenwu during Northern Zhou and Sui Dynasty and the Princess Xiangyang daughter of Yuwen Tai, posthumously honored as Empress Taimushunsheng
• Wife
  • Empress Zhangsun (created 626, d. 636), mother of Crown Princes Chengqian and Zhi, Prince Tai, and Princesses Changle, Jinyang, and Xincheng
• Major Concubines
  • Consort Xu Hui (徐惠) (627-650), titled Chongrong (充容), posthumously honored Xianfei (賢妃)
  • Consort Yang, daughter of Emperor Yang of Sui, mother of Princes Ke and Yin
  • Consort Yin, mother of Prince You
  • Consort Wang, mother of Prince Yun
  • Consort Yan, mother of Princes Zhen and Xiao
  • Consort Wei, mother of Prince Shen and Princess Linchuan
  • Consort Yang, mother of Prince Fu
  • Consort Yang, formerly wife and princess of Li Yuanji the Prince of Qi, mother of Prince Ming
  • Consort Wu, later wife and empress of Emperor Gaozong, later Emperor of Zhou, commonly known as Wu Zetian
• Sons
  • Li Chengqian (李承乾), initially the Prince of Changshan (created 620), later the Prince of Zhongshan (created 622), later the Crown Prince (created 626), later reduced to commoner rank (deposed 643), posthumously honored as Prince Min of Changshan
  • Li Kuan (李寬) (d. 620?), posthumously created the Prince of Chu
  • Li Ke (李恪), initially the Prince of Changsha (created 620), later the Prince of Han, later the Prince of Shu (created 628), later the Prince of Wu (created 636, forced to commit suicide 653), posthumously created the Prince of Yulin
  • Li Tai (李泰), initially the Prince of Yidu (created 620), later the Prince of Wei (created 621), later the Prince of Yue (created 628), later the Prince of Wei (created 636), later demoted to the Prince of Donglai (demoted 643), later the Prince of Shunyang (created 643), later Prince Gong of Pu (created 647)
  • Li You (李祐), initially the Prince of Yiyang (created 625), later the Prince of Chu, later the Prince of Yan (created 628), later the Prince of Qi (created 636, forced to commit suicide 653)
  • Li Yin (李愔), initially the Prince of Liang (created 631), later the Prince of Shu (created 636), later reduced to commoner rank (deposed 653), later the Prince of Peiling (d. 667), posthumously created Prince Dao of Shu
  • Li Yun (李惲), initially the Prince of Tan (created 631), later the Prince of Jiang (created 636, committed suicide 674)
  • Li Zhen (李貞), initially the Prince of Han (created 631), later the Prince of Yue (created 636, committed suicide 688)
  • Li Zhi (李治), initially the Prince of Jin (created 631), later the Crown Prince (created 643), later Emperor Gaozong of Tang
  • Li Shen (李慎), initially the Prince of Shen (created 631), later the Prince of Ji (created 636), later reduced to commoner rank (deposed and d. 688)
  • Li Xiao (李囂), Prince Shang of Jiang (created 631, d. 632)
  • Li Jian (李簡), the Prince of Dai (created and d. 631)
  • Li Fu (李福), the Prince of Zhao (created 639, d. 670)
  • Li Ming (李明), initially the Prince of Chao (created 647), later demoted to Prince of Lingling (demoted 680 or 681, forced to commit suicide 682)
• Daughters
  • Princess Xiangcheng (d. 651)
  • Princess Runan
  • Princess Nanping
  • Princess Sui'an
  • Princess Changle
  • Princess Yuzhang
  • Princess Baling (forced to commit suicide 653), posthumously created the Princess Bijing
  • Princess Pu'an
  • Princess Dongyang
  • Princess Linchuan (d. 682)
  • Li Jing (李敬), the Princess Qinghe (d. 664)
  • Li Shu (李淑), the Princess Lanling
  • Princess Jin'an
  • Princess Ankang
  • Princess Xingxing
  • Princess Chengyang
  • Princess Gaoyang (forced to commit suicide 653), posthumously created the princess Hepu
  • Princess Jinshan
  • Li Mingda (李明達), the Princess Jinyang
  • Princess Changshan (d. 656)
  • Princess Xincheng

Literary and other cultural references

• Taizong was the subject of a 64-chapter (in eight volumes) The Novel of the Prince of Qin of the Great Tang (大唐秦王詞話 Datang Qin Wang Cihua) by Zhu Shenglin (諸聖鄰) of the Ming Dynasty. The novel is also known as The Biography of the Prince of Qin of the Tang Dynasty (唐秦王本傳 Tang Qin Wang Benzhuan), Romance of Tang (唐傳演義 Tang Chuan Yanyi), and Romance of the Prince of Qin (秦王演義 Qin Wang Yanyi).
• Hong Kong TVB made a television drama about Li Shimin's adventure based on the The Novel of the Prince of Qin of the Great Tang (大唐秦王詞話). TVB's 1983 martial arts drama The Foundation also featured a young Li Shimin prominently as one of its three leads (and later, villain).
• In the great Chinese epic novel Journey to the West, there is a fictional account of Li Shimin’s invention of the door gods to protect him from a vengeful beheaded dragon, after the dragon's failure to protect him.

Notes

References

ISBN links support NWE through referral fees

• Eberhard, Wolfram. A history of China. Berkeley: University of California Press, 1977. ISBN 0520032276.
• Fitzgerald, C. P. Son of heaven [a biography of Li Shih-Min, founder of the Tʻang dynasty. New York: AMS Press, 1971. ISBN 0404024041.
• Grousset, René. The empire of the steppes; a history of central Asia. New Brunswick, NJ: Rutgers University Press, 1970. ISBN 0813506271.
• Tang, Taizong, and Thomas D. Carroll. Account of the T'u-yü-hún in the History of the Chin dynasty Tsin shu. (Chinese dynastic histories translations, no. 4.) Berkeley: University of California Press, 1953.
• Twitchett, Denis Crispin, and John King Fairbank. The Cambridge history of China. Cambridge, UK: Cambridge University Press, 1978. ISBN 0521214475.
• Wechsler, Howard J. Factionalism during the early T'ang dynasty. (Conference on T'ang Studies) Cambridge, UK: Cambridge University, 1969. [Papers)
• Wright, David Curtis. The history of China. (The Greenwood histories of the modern nations.) Westport, CT: Greenwood Press, 2001. ISBN 031330940X.

Preceded by: Emperor Gaozu of Tang	Emperor of Tang Dynasty 626-649	Succeeded by: Emperor Gaozong of Tang
	Emperor of China (most regions) 626-649
Preceded by: Liang Shidu (Emperor of Liang)	Emperor of China (Northern Shaanxi/Western Inner Mongolia) 628-649