Emperor Taizong of Tang
Emperor Taizong of Tang, previously Prince of Qin, personal name Li Shimin, was the second emperor of the Tang dynasty of China, ruling from 626 to 649. He is traditionally regarded as a co-founder of the dynasty for his role in encouraging his father Li Yuan to rebel against the Sui dynasty at Jinyang in 617. Taizong subsequently played a pivotal role in defeating several of the dynasty's most dangerous opponents and solidifying its rule over China proper.
Taizong is considered to be one of the greatest emperors in China's history, and henceforth his reign became regarded as the exemplary model for which all future emperors were measured. His era, the "Reign of Zhenguan" is considered a golden age in ancient Chinese history and was treated as required studying material for future crown princes. Taizong continued to develop imperial examination systems. He asked his officials to be loyal to policies, not people, in order to eliminate corruption. Under the Zhenguan era, Tang China flourished economically and militarily. For more than a century after his death, China enjoyed prosperity and peace brought about by the solidification of imperial protection over the Chinese regions. In territorial extent, it covered most of the territories previously held by the Han dynasty as well as parts of modern-day Korea, Vietnam, Russia, Mongolia, Xinjiang, and Central Asia. This era of consolidation and conquest laid the foundation for Xuanzong's reign, which is considered to be the height of the Tang dynasty.
In 630, Emperor Taizong sent his general Li Jing against the Eastern Turks, defeating and capturing their Jiali Khan Ashina Duobi and destroying their power. This made Tang the dominant power in East and Central Asia, and Emperor Taizong subsequently took the title Khan of Heaven. He also launched a series of campaigns against the oasis states of the Tarim Basin, and against their main ally, the Western Turks. During his reign, Tang armies annexed Karakhoja in 640, Karasahr in 644, and Kucha in 648. Eventually, the Tang defeated and annexed the Western Turkic Khaganate after Su Dingfang defeated Qaghan Ashina Helu in 657.
Unlike much of the nobility in his time, Emperor Taizong was a frank rationalist and scholar of logic and scientific reason, openly scorning superstitions and claims of signs from the heavens. He also modified important rites in order to ease the burden of agricultural labour. The modern Chinese historian Bo Yang opined that Emperor Taizong achieved greatness by enduring criticism which others would find difficult to accept whilst trying hard not to abuse his absolute power, as well as by employing capable chancellors such as Fang Xuanling, Du Ruhui, and Wei Zheng. Emperor Taizong's wife Empress Zhangsun also proved to be a capable assistant.
Early life
Li Shimin was born in 598 at Wugong, 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, both of whom were daughters of Dugu Xin, a major Xianbei general during Sui's predecessor dynasty Northern Zhou. Li Shimin's mother, Li Yuan's wife Duchess Dou, was a daughter of Dou Yi, the Duke of Shenwu, and his wife, Northern Zhou's Princess Xiangyang. Li Shimin was also of partial Xianbei descent. Duchess Dou bore Li Yuan four sons—an older brother to Li Shimin, Li Jiancheng, and two younger brothers, Li Yuanba, who would die in 614, and Li Yuanji – and at least one daughter. Li Yuan named Li Shimin "Shimin" as a shortened form of the phrase "save the earth and pacify the people". Li Shimin apparently showed talent early in his life, and in 613, the official Gao Shilian, impressed with him, gave him a niece in marriage as his wife; he was 14 and she was 12. In 615, when Emperor Wen's son and successor Emperor Yang was ambushed by Eastern Turkic forces under Shibi Khan at Yanmen Commandery, 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, apparently doing so with distinction. In 616, when Li Yuan was put in charge of the important city of Taiyuan, he brought Li Shimin with him to Taiyuan, while leaving at least three other sonsLi Jiancheng, Li Yuanji, and Li Zhiyun at the ancestral home Hedong.Participation in the rebellion against Sui rule
Emperor Yang was soon dissatisfied with Li Yuan and Wang Rengong, the governor of Mayi Commandery, over their inability to stop Eastern Turkic incursions and the growing strength of agrarian rebels, particularly the Eastern Turkic-supported Liu Wuzhou, who soon rose against Wang, killed him, and captured Emperor Yang's secondary palace near Taiyuan. Li Yuan also became fearful of a prophecy that the next emperor would be named Li—Emperor Yang had previously killed another official, Li Hun, and Li Hun's clan over his fear that Li Hun's nephew, Li Min, would seize the throne.Fearful for his life, Li Yuan considered rebellion. However, he did not know that Li Shimin had also been secretly discussing plans for rebellion with Li Yuan's associates Pei Ji and Liu Wenjing. Once Li Shimin's plans matured, he had Pei inform Li Yuan of them—and also had Pei warn Li Yuan that if it were revealed that Li Yuan had had sexual relations with some of Emperor Yang's ladies in waiting at the secondary Jinyang Palace, all of them would be slaughtered. Li Yuan agreed to rebel, and after secretly summoning Li Jiancheng and Li Yuanji from Hedong and his son-in-law Chai Shao from the capital Chang'an, he declared a rebellion, claiming to want to support Emperor Yang's grandson Yang You the Prince of Dai, nominally in charge at Chang'an with Emperor Yang at Jiangdu, as emperor. He made both Li Jiancheng and Li Shimin major generals and advanced southwest, toward Chang'an. He gave Li Shimin the title of Duke of Dunhuang. After defeating local Sui forces loyal to Emperor Yang, he defeated a Sui army of 30,000 men under the command of a veteran general of the wars in Korea outside of modern-day Beijing.
However, when Li Yuan arrived near Hedong, his army was bogged down by the weather. With food running out, there were rumors that the Eastern Turks and Liu Wuzhou would attack Taiyuan. Li Yuan initially ordered retreat, but at the earnest opposition by Li Jiancheng and Li Shimin, continued to advance. After defeating Sui forces at Huoyi, he decided to leave a small contingent to watch over Hedong while advancing across the Yellow River into Guanzhong. Once he did, he headed for Chang'an himself, while sending 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. Meanwhile, Li Shimin's sister Pingyang had also risen in rebellion in support of him, and she was able to gather a sizeable army and capture some cities. She joined forces with Li Shimin and her husband Chai Shao. Soon, Li Yuan reconsolidated his forces and put Chang'an under siege. In winter 617, after defeating a large Sui army, he captured Chang'an from imperial forces and declared Yang You emperor. He had himself made regent, Li Shimin made the Duke of Qin, and created the Prince of Tang. Meanwhile, most of the Sui territories and armies did not recognize Emperor Gong as emperor, continuing to support the former Emperor Yang.
Li Yuan's control of the Chang'an region became almost immediately contested by the rebel ruler Xue Ju, the Emperor of Qin, who sent his son Xue Rengao toward Chang'an. Li Yuan sent Li Shimin to resist Xue Rengao, and Li Shimin defeated Xue Rengao at Fufeng, temporarily causing Xue Ju to toy with the idea of surrendering to Li Yuan, although Xue was subsequently dissuaded by his strategist Hao Yuan from doing so.
In spring 618, with Sui's eastern capital Luoyang under attack by 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 instead intending to test 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 either them or Li Mi for control of Luoyang at this stage, withdrew. Li Yuan subsequently changed Li Shimin's title to Duke of Zhao.
In summer 618, when news arrived at Chang'an that Emperor Yang had been killed at Jiangdu in a coup led by the general Yuwen Huaji, Li Yuan had Emperor Gong yield the throne to him, establishing Tang dynasty as its Emperor Gaozu. He created Li Jiancheng crown prince but created Li Shimin the Prince of Qin, also making him Shangshu Ling, the head of the executive bureau of the government and a post considered one for a chancellor, while continuing to have Li Shimin serve as a major general as well.
During Emperor Gaozu's reign
Campaign to reunify the empire
The first thing that Li Shimin had to deal with was another incursion by Xue Ju, as Xue attacked Jing Prefecture and Emperor Gaozu sent Li Shimin to resist Xue. Li Shimin established his defenses and refused to engage Xue to try to wear Xue Ju out, but at that time, he was afflicted with malaria, and he let his assistants Liu Wenjing and Yin Kaishan take command, ordering them not to engage Xue Ju. Liu and Yin, however, did not take Xue Ju seriously, and Xue Ju ambushed them at Qianshui Plain, crushing Tang forces and inflicting 50–60% casualties. Li Shimin was forced to withdraw back to Chang'an, and Liu and Yin were removed from their posts. Xue Ju, in light of his victory, was ready to launch an assault on Chang'an itself, under Hao Yuan's advice, but suddenly died of an illness in fall 618 and was succeeded by Xue Rengao. Emperor Gaozu then sent Li Shimin against Xue Rengao. Three months after Xue Rengao took the throne, Li Shimin engaged him, and after a fierce battle between Li Shimin and Xue Rengao's major general Zong Luohou, Li Shimin crushed Zong's forces and then attacked Xue Rengao. Xue Rengao was forced to withdraw into the city of Gaozhi, and once he did, his soldiers began surrendering to Li Shimin en masse. Xue Rengao was himself forced to surrender. Li Shimin had him delivered to Chang'an, where he was executed. Around new year 619, Emperor Gaozu made Li Shimin Taiwei 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 winter 619, Liu had crushed Pei's forces and taken over nearly all of modern Shanxi. Emperor Gaozu, shocked at the development, considered abandoning the region altogether. Li Shimin opposed doing so and offered to lead the army against Liu. Emperor Gaozu agreed and commissioned him with an army. He crossed the Yellow River and approached Liu's major general Song Jingang but did not engage him, choosing to try to wear Song out, only having his subordinates Yin Kaishan and Qin Shubao engage the other Dingyang generals Yuchi Jingde and Xun Xiang in relatively low-level engagements. Eventually, in 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 after Li Shimin chased further, both Liu and Song fled to the Eastern Turks. All of Dingyang territory fell into Tang hands.
In summer 620, Emperor Gaozu again commissioned Li Shimin against a major enemy—the former Sui general Wang Shichong, who had 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. Meanwhile, his subordinates took Zheng cities one by one. By winter 620, most of Zheng territory, other than Luoyang and Xiangyang, defended by Wang Shichong's nephew Wang Honglie, had submitted to Tang. Wang sought aid from 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 next, agreed. He sent his official Li Dashi to try to persuade Li Shimin to withdraw, but Li Shimin detained Li Dashi and gave no response. Meanwhile, during the campaign, Li Shimin chose some 1,000 elite soldiers, clad in black uniform and black armor, commanded by himself, to serve as advance troops, with Qin Shubao, Yuchi Jingde, Cheng Zhijie, and Zhai Zhangsun as his assistants.
By spring 621, Luoyang was in desperate situation, and Xia forces had not yet arrived, but Tang troops had also suffered serious casualties, as Luoyang's defenses, aided by powerful bows and catapults, were holding. 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 to siege Luoyang. When Xia forward troops arrived first, Li Shimin surprised and defeated them, and then sent Dou a letter suggesting that he withdraw. Dou would not do so, and, against the advice of his wife Empress Cao and secretary general Ling Jing 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 position 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 as his generals pointed out that his only hope was Dou, he surrendered. Xia forces, after initially fleeing back to their capital Mingzhou, also surrendered. Zheng and Xia territory were Tang's. Li Shimin returned to Chang'an in a grand victory procession and, to reward Li Shimin, 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". Meanwhile, Li Shimin's staff, already full of generals and strategists, were supplemented with a number of literary men.
The former Xia territory did not remain in Tang hands for long. In the winter of 621, the Xia general Liu Heita rose against Tang rule, claiming to be avenging Dou, whom Emperor Gaozu had executed against Li Shimin's wishes after he had been brought back to 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, the Prince of Huai'an; Li Xiaochang, the Prince of Yi'an; and Li Shiji. By the end, he had recovered almost all of the former Xia territory, established his capital at Mingzhou, and proclaimed himself the Prince of Handong. Emperor Gaozu finally sent Li Shimin and Li Yuanji against him in 622 and, after some indecisive battles, Li Shimin defeated him by first erecting a dam across the Ming River and then destroying it, with the resultant flood destroying the rebel army. Liu fled to the Eastern Turks, while Li Shimin then headed east and defeated Xu. After leaving Li Shiji, Li Shentong, and Ren Gui to continue attacking Xu, Li Shimin returned to Chang'an.