Independent warlords now ruled different parts of China and Daizong could not command the kind of authority Xuanzong had at the beginning of his reign. Churches, synagogues, and temples of Manichaeism and Zoroastrianism remained closed and these faiths proscribed. In 626 Emperor Gaozu choose Li Yuanji over Li Shimin to lead a crucial battle against the Eastern Tujue the trouble came to a head. She was so lovely, she attracted the attention of his son. He created Li Shimin the Duke of Dunhuang. Known for taking criticism constructively, Taizong was later regarded as an exemplary model against which all future emperors were measured. In 615 when Emperor Yang of the Sui Dynasty 581-618 was besieged by the Tujue's army, Li volunteered to lead a rescue operation thus making quite a name for himself at the age of sixteen.
Fang accused the emperor of injustice, because he sent his soldiers to a certain death in a distant country, whereas criminals condemned to death could count on three reviews before the execution would take place. After contracting dysentery, Taizong dies at Chang'an. He composed many poems and was an accomplished calligrapher. In territorial extent, it covered most of the territories previously held by the , including parts of modern , , and regions as far as eastern. It was not always easy for a powerful and highly accomplished monarch to hear disagreement, frank criticism, or interventions, but the emperor restrained himself and rewarded his critics when their arguments were reasonable and sound. Li Yuan subsequently changed Li Shimin's title to Duke of Zhao. Gaozong would have to continue his father's wars in the Tarim Basin as the turks revolted and the Tang army was sent to put the rebellions down.
Li Shimin had Yuchi summon Fang and Du back to his mansion secretly, and then on one night submitted an accusation to Emperor Gaozu that Li Jiancheng and Li Yuanji were committing adultery with Emperor Gaozu's concubines. Unlike rulers of later dynasties, Taizong also embraced cultural diversity. Furthermore, the encampments should be far away from county or prefectural seats, so the students and elderly people were not required to come out to meet the emperor. The Tang Dynasty also invented gunpowder, waterproofing, fireproofing, gas stoves, and air conditioning. Emperor Taizong accepted Wen's suggestion and established a number of prefectures to accommodate the Turks, leaving them governed by their chieftains without creating a new khan to govern them. Confucianism is based on the teachings of the Chinese philosopher Confucius while Daoism has its roots in the book of the Daodejing.
Meanwhile, he appeared to begin to reshuffle government further—which he had already begun after being created crown prince—by dismissing his father's trusted advisors Xiao Yu and Chen Shuda, making his own trusted advisors chancellors. In 649, Emperor Taizong contracted dysentery and soon after died at Hanfeng Palace in Chang'an. Li Jiancheng persuaded Emperor Gaozu to remove Fang and Du, as well as Li Shimin's trusted guard officers Yuchi Gong and Cheng Zhijie, from Li Shimin's staff. In 617, Li Yuan, Emperor Taizong's father, was appointed governor of Taiyuan. He is traditionally regarded as a co-founder of the dynasty for his role in encouraging , his father, to rebel against the at in 617.
Its narrative of the Koguryŏ invasion follows the Xin Tangshu closely, and both are more detailed than the Jiu Tangshu. In fall 636, Empress Zhangsun died. This account may correspond to the conquest of the and reunification of China by r. The dynasty's founder, Li Yuan, was the governor of Taiyuan and a prominent military leader; he also claimed descent from Laozi, the founder of Taoist school of thought. Korean authors usually focus on Taizong in connection with the Koguryŏ campaign, or as the adversary of Yŏn Kaesomun, in academic articles and fiction alike. The modern Chinese historian 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 using as a negative example , as well as through his employment of capable such as , and. It featured a young Li Shimin prominently as one of its three leading characters.
Emperor Taizong spared Ashina Duobi but detained him at Chang'an, and he considered what to do with the. . Xue Rengao was himself forced to surrender. Then, the western world became fragmented because of the ruin of the Roman Empire, while the Tang Dynasty was just at its most prosperous time under the wise reign of Emperor Taizong. One such disaster was the building of a palace that took 2,000,000 man-days of labor, which Taizong had destroyed because he decided the environment of the area where the palace was built was too hot and the palace itself was too grand.
The expansion of China's power into Central Asia under Emperor Taizong seems to have been noticed in the West. The many Yŏnhaengnŏk had created a textual double of that world, which was now familiar even to those who had not travelled to the Qing court. Taizong was a brilliant strategist and charismatic leader whose contributions to the overthrow of the Sui were rewarded when his father named him Qinguogong, a vassal of the state, and later Qin Wang, Duke of the state of Qin. So he cherished the labor forces and never requisitioned them randomly. Viewing Sui's Emperor Yang as a negative example, he frequently solicited criticism, rewarding those officials willing to offer them, particularly Wei and Wang Gui.
During Taizong's rule China would have many years of peace and prosperity. The fear drove him to fashion a plot to eliminate Li and grasp his military power. After his success in protecting China he expanded his Empire westward. Qu Zhisheng offered to submit, but Hou demanded a surrender, which Qu Zhisheng refused. These hostilities between the and Tang would continue until the defeat and in 657 under Taizong's successor, Gaozong. People say that it is the place where Tang Taizong stayed overnight when he campaigned in the east. He revived the policies of the early Tang Dynasty and initiated reforms in government and the military.