Emperor Taizong of Tang Dynasty, personal name Li Shimin, was the second emperor of the Tang Dynasty of China, ruling from 626 to 649. As he encouraged his father, Li Yuan (later Emperor Gaozu) to rise against Sui Dynasty rule at Taiyuan in 617 and subsequently defeated several of his most important rivals, he was ceremonially regarded as a co-founder of the dynasty along with Emperor Gaozu.
Background
Li Shimin was born in 599 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, as Li Shimin's grandmother Duchess Dugu was a sister of Empress Dugu Qieluo – both were daughters of Dugu Xin, a major general during Sui's predecessor dynasty Northern Zhou. Li Shimin's mother was Li Yuan's wife Duchess Dou, who was a daughter of Dou Yi the Duke of Shenwu and Dou Yi's wife, Northern Zhou's Princess Xiangyang. Duchess Dou bore Li Yuan four sons—an older brother to Li Shimin, Li Jiancheng, and two younger brothers, Li Xuanba (who would die in 614) and Li Yuanji – and at least one daughter (the later Princess Pingyang). Li Yuan named Li Shimin "Shimin" as a shortened form of the phrase "save the earth and pacify the people" (jishi anmin). Li Shimin apparently showed talent early in his life, and in 613, the official Gao Shilian, impressed with him, gave him a niece (the later Empress Zhangsun) 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 Tujue forces at Yanmen (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, apparently doing so with distinction. In 616, when Li Yuan was put in charge of the important city of Taiyuan, Li Shimin followed his father to Taiyuan, while leaving at least three other sons—Li Jiancheng, Li Yuanji, and Li Zhiyun (by Li Yuan's concubine Lady Wan) – at the ancestral home Hedong (in modern Yuncheng, Shanxi).
Career
By 624, the Tang had largely reunified the old Sui realm and successfully fended off the Turks' encroachments. Conflicts arose between the heir apparent, selected according to the Chinese tradition of primogeniture, and his younger brother, a distinguished military leader who also established as early as 621 an academy to patronize classical literature and scholarship, winning a large Confucian following.
On 2 July 626, Li Shimin launched the coup of Xuanwu Gate, ambushing and killing both his elder brother, the Crown Prince, and a younger brother at the palace entrance. All male offspring of the two murdered brothers were consequently executed also. The Tang founding emperor was forced to abdicate and 'retire' on 3 September. Though standard histories tried to conceal the near-patricidal atmos¬phere of this succession, a popular Buddhist literary work accused Li Shimin of fratricide and incarcerating his father, revealing that the last years of the 'retired' emperor may not have been happy. While shocking by Confucian standards of filial piety, the violent means by which Li Shimin came to power were in keeping with the principle of tanistry, whereby the most capable of eligible heirs should lead the tribe. This principle was exercised not only in the early stages of the Tang, but also later in the dynasty, as well as by many other dynasties founded by the steppe people who ruled over part or all of what is now China.
Li Shimin, posthumously known as Emperor Taizong, began the consolidation and expansion of the new Tang empire. He enlarged the newly established civil service examinations, tapping into a source of Confucian talent and loosening the aristocracy's strong hold on political power. He learned his lessons from Emperor Yang's negative example, adopted a frugal fiscal policy, and encouraged criticism and dissent, exhibiting a tolerance almost unique among China's emperors. These measures, together with the implementation of the Tang's 'equal land' policy of joint state-private land ownership (taken over and adapted from the Tuoba), led to rapid economic recovery and prosperity.
The Tang completely destroyed the Eastern Turk power in 629-30 and captured its most powerful ruler, Jieli Khan, subsequently adopting an enlightened ethnic policy of 'equal treatment of Chinese and "barbarians'", leading to half of the court positions being taken up by Turks who had submitted and other ethnic leaders. The emperor assumed the title 'Heavenly Khan' in spring 630, asserting his sovereignty over the vast steppeland and the nomadic tribes who inhabited it. It was during his reign that Nestorian Christians were allowed to settle in the capital, and the Byzantine Emperor Theodosius sent a mission to his court in 643.
In his mid to late forties, Taizong grew less tolerant and more extravagant. He commanded an expedition against Koguryo in 645, which was no more suc¬cessful than the attempts of Emperor Yang. Undaunted, he turned his attention westward and initiated hostilities against the Western Turks. Moderating his earlier preference for Daoism, Taizong also became more receptive to Buddhism, likely motivated by the faith's important role in the Tang's 'foreign policy'.
Chronically ill, Taizong frequently withdrew from his court duties and appointed his heir apparent as acting regent for long periods. Yet he clearly felt that maintaining his standing among the steppe peoples was of great importance, because in the summer of 646 he decided to make a journey to the frontier prefecture of Lingzhou to meet nomadic chieftains and have them reassert their allegiance. Taizong died on 10 July 649, at the age of fifty.