In the thirteenth year of the Great Cause (617), the ranks of the world who rose up against the Sui swarmed, and the Jiangdu (now Yangzhou, Jiangsu), where Emperor Yang of the Sui Dynasty was located, was isolated. Liu Wenjing, the commander of Jinyang, and Pei Lian, the eunuch of Jinyang Palace, are all close friends of Li Shimin. Li Shimin conspired with Liu Wenjing, the commander of Jinyang County, to raise troops.

After the strategy of raising troops to rebel was decided, Li Yuan did not know about it. Li Shimin wanted to tell the truth, but he was worried that Li Yuan would not listen. Li Shimin privately found Pei Yuan to discuss, and Pei Lin chose several beauties from Jinyang Palace, and after Li Yuan was drunk, he spent the night with him. Then, Pei Lin told Li Yuan about Li Shimin's plan, and Li Yuan was shocked. Pei Lin said: "Arrange for the palace maid to serve, after the matter is exposed, you will be killed, I am doing this to persuade you to make up your mind to raise troops." Li Shimin took the opportunity to report the entire plan to Li Yuan. Li Yuan resolutely disagreed at first, and also said that he would send Li Shimin to report to the official. After a while, Li Yuan still agreed to raise troops and said to Li Shimin: "I love you, how can I bear to denounce you!"

In the second lunar month of the thirteenth year of the Great Cause (617), Liu Wuzhou, the captain of Yingyang Mansion stationed in Mayi (now Shuozhou City, Shanxi) under Li Yuan, launched a mutiny, killed Wang Rengong, the Taishou of Mayi, and proclaimed himself the Son of Heaven according to Mayi. In the third lunar month, Liu Wuzhou broke through Loufu County, occupied Fenyang Palace, and colluded with the Turks to plot south to fight for the world. Emperor Yang was furious when he heard the news and wanted to mention Li Yuan to Jiangdu to punish the crime. In this critical situation, Li Shimin said: "The matter is urgent, and we can do it." His surrounding henchmen Pei Lian, Xu Shixu, and Wu Shiwei also persuaded Li Yuan to raise troops, and Li Yuan finally made up his mind to oppose Sui. Therefore, under the pretext of guarding against Liu Wuzhou and the Turks going south, Li Yuan sent Li Shimin, Liu Wenjing, Changsun Shunde, Liu Hongji and others to various places to recruit troops, and recruited thousands of people in a short time.

Wang Wei and Gao Junya, deputy guards of Taiyuan, saw Li Yuan recruiting troops and horses, and suspected that Li Yuan was going to rebel, so they plotted to trick Li Yuan's father and son into praying for rain at the Jin Temple, get rid of the Li family, and ask Emperor Yang of Sui for a reward. Unexpectedly, this conspiracy was learned by Liu Shilong, the head of Jinyang Township, and Li Yuan was informed. On the fifteenth day of the fifth lunar month in the thirteenth year of the Great Cause (617), Li Yuan and Li Shimin preemptively instructed Sima Liu Zhenghui of Kaiyang Mansion to denounce Wang Wei and Gao Junya of secretly colluding with the Turks and luring the Turks into the Central Plains of Kou, so as to imprison the two. On the seventeenth day of the fifth lunar month, tens of thousands of Turkic troops happened to attack Jinyang, and Li Yuan immediately justifiably ordered the two to be pushed out and beheaded. In June, he sent his second sons Li Jiancheng and Li Shimin to lead an army to attack and kill Chenggao Deru of Xihe County, who refused to die. At the same time, Li Yuan set up an empty city plan to scare off the Turkic army. Then, Li Yuan began to make preparations for the rebellion against the Sui.

In the seventh lunar month of the thirteenth year of the Great Cause (617), Li Yuan led an army of 30,000 to swear and officially set up an army. In the published article, he reprimanded Emperor Yang of Sui for listening to slanderous rumors, killing Zhongliang, and recklessly using military force, which caused the people's resentment to boil. Soon, Li Yuan led his sons to break through Qu Tutong in the garrison pass and occupy Daxing City, the capital of Sui. Li Yuan supported Yang Yu as the emperor, was for Emperor Gong of Sui, and respected Emperor Yang of Sui as the emperor, appointed himself as the prime minister, and entered the Tang Dynasty.

After taking the oath, Li Yuan and his eldest son Jiancheng and his second son Shimin waved their troops south, and successively broke through the Sui Yingyalang general Song Laosheng who defended Huoyi (now Huo County, Shanxi), crossed the Yellow River, and besieged Qu Breakthrough, who was guarding the east of the river, without attacking. Quickly advance to the southwest. At that time, Emperor Yang of the Sui Dynasty was far away in Jiangdu (now Yangzhou, Jiangsu), and the Sui army in the Guannai was weak; The Wagang Army of the Central Plains and Wang Shichong fought fiercely, and they had no time to look west. Therefore, the Li father and son marched quickly, and entered Chang'an in the 11th lunar month of the 13th year of the Great Cause (617).

Soon after Li Yuan entered Chang'an, he announced that Emperor Yang of Sui was respected as Emperor Taishang, and Yang Yu, the grandson of Emperor Yang, was established as emperor, and Yuan Yining was changed to Emperor Gong of Sui. Emperor Gong enshrined Li Yuan as the king of Tang, the prime minister, and Shang Shuling, and Li Jiancheng as the prince of Tang; Li Shimin was Jing Zhaoyin and was renamed the Duke of Qin; Feng Li Yuanji was named the Duke of Qi.

In 618, the Jiangdu coup d'état, Emperor Yang of Sui was killed by Yu Wenhua and other rebels.

Li Yuan took this opportunity to force Emperor Gong of Sui to take the throne in May of the same year and establish the Tang Dynasty, that is, Tang Gaozu. The capital city was renamed Chang'an, and the eldest son Li Jiancheng was the crown prince, the second son Li Shimin was the king of Qin, and the fourth son Li Yuanji was the king of Qi.

Li Yuan is a descendant of Li Wei, the founding monarch of Xiliang during the Sixteen Kingdoms period, and has been a dignitary for generations. Longxi Chengji (now northwest of Qin'an County, Gansu Province), one said that Longxi Didao (now Lintao County, Gansu Province), ancestral home of Yaoshan (now Longyao County, Xingtai City).

Li Yuan's grandfather, Li Hu, was one of the Eight Pillars of the Western Wei Dynasty. Li Yuan's father, Li Xun, was the official of the Northern Zhou Dynasty, the governor of Anzhou, and the general of the Zhu State, and was awarded the title of Duke of Tang State. Li Yuan's mother was the sister of Empress Dugu of Emperor Wen of Sui.

In the first year of Tianhe of the Northern Zhou Dynasty (566), Li Yuan was born in Chang'an. When Li Yuan was seven years old, his father Li Yu died, and he was named the Duke of Tang Guo. When Li Yuan grew up, he was free and easy, cheerful, and tolerant.

In the first year of the emperor's reign (581), Emperor Wen of Sui was conceded by Emperor Jing of the Northern Zhou Dynasty to establish the Sui Dynasty. Emperor Wen of Sui appointed Li Yuan as Qianniu Beishen (the emperor's military attache of the Praetorian Guard). Because Li Yuan's aunt was the Dugu Empress of Emperor Wen of Sui, Emperor Wen of Sui was particularly close to Li Yuan, and served as the assassin of Qiaozhou, Longzhou, and Qizhou.

Once, Xuanyuan Jingtian knew that Li Yuan was the new human emperor, and specially instructed Li Yuan in person, "Your bones are amazing, you will be the lord of the world, may you love yourself, remember and remember." After saying that, he returned to Liyan Villa.

At the beginning of Emperor Yang of Sui's accession to the throne, Li Yuan successively served as the Taishou of Xingyang (now Xingyang, Henan) and Loufu (now Jingle County, Shanxi), and was later appointed as the young eunuch and the guard of the palace.

In the spring of the ninth year of Daye (613), when Emperor Yang of Sui conquered Goguryeo, Li Yuan supervised the transportation of grain and grass in Huaiyuan Town. In the sixth lunar month of the same year, Yang Xuangan took advantage of the people's anger to raise troops against the Sui, and Li Yuan was ordered by Emperor Yang of the Sui Dynasty to guard Honghua County (now Qingyang County, Gansu), and also knew the military of Guanyou.

During this period, Li Yuan made friends with heroes all over the world and was suspicious of Emperor Yang of Sui. It happened that there was an edict ordering Li Yuan to go to the place where Emperor Yang of Sui went on his tour, but Li Yuan did not go due to illness. At that time, Li Yuan's nephew, the Queen, was in the harem, and Emperor Yang of Sui asked Wang: "Why didn't your uncle come for a long time?" Wang replied that Li Yuan was sick, and Emperor Yang of Sui asked again: "Are you going to die?" Li Yuan knew that he would become more and more frightened in the future, so he drank alcohol and accepted bribes to protect himself.

In the eleventh year of the Great Cause (615), Li Yuan was transferred to Shanxi Hedong as the ambassador of consolation, and when he arrived at Longmen, he encountered the peasant uprising of Muduan'er, Li Yuan led the army to defeat the rebel army, collected more than 10,000 people, and greatly increased his strength. He also attacked the Jiangzhou thief Chai Baochang and reduced tens of thousands of people.

In the following year (616), he was promoted to the rank of general of the Right Guard. The Turks invaded the border fortress, and Emperor Yang of Sui asked him to attack the Turks in the north with Wang Rengong, the commander of Mayi County. But they had very few soldiers. Li Yuan selected 2,000 cavalrymen who were good at cavalry and archery, ate and lived in cavalry and archery, imitated the Turkic soldiers, and showed the Turks their shooting and hunting gallops in their leisure time. Li Yuan had another soldier who was good at archery as an ambush. When encountering the Turkic soldiers, Li Yuan ordered an ambush and attack, and as a result, the Turks were defeated.

At the beginning of the establishment of the Tang Dynasty, the territory was limited to the area of Guanzhong and Hedong, and had not yet completely ruled the whole country, so Li Yuan often sent his sons Li Shimin, Li Jiancheng, and Li Yuanji to go on expeditions to gradually eliminate the separatist forces in various places.

In the sixth lunar month of the first year of Wude (618), Li Shimin attacked Xue Ju, Xue Renguo and his son who possessed Lanzhou and other places in present-day Gansu.

In the second year of Wude (619), the Tang Dynasty used counter-tactics to intensify the internal contradictions of Li Rail's group, thus capturing and killing Li Rail and pacifying the Hexi Corridor. In the same year, Liu Wuzhou and Song Jingang colluded with the Turks, invaded Hedong, and occupied Taiyuan. Li Yuanji, Pei Lin and others were defeated and fled. Later, Li Shimin went to Hedong, recovered Taiyuan and eliminated Liu Wuzhou's forces. Liu Wuzhou and Song Jingang fled to the Turks and were soon killed. At that time, the Yellow River Basin formed a three-legged trend of the Xia regime Dou Jiande, the Zheng regime Wang Shichong and the Tang Dynasty. In 620, Li Shimin was ordered to lead an army east against Wang Shichong, and Dou Jiande and Wang Shichong allied against Li Shimin's army.

In the fourth year of Wude (621), Li Shimin captured Dou Jiande in the first battle of Wujiaoguan. prompted Wang Shichong to surrender. In the sixth year of Wude (623), the crown prince Li Jiancheng captured and beheaded Liu Heimin, the rest of Dou Jiande, and pacified the Hebei region. In the seventh year of Wude (624), Gao Kaidao was killed by his subordinate Zhang Jinshu, and Zhang Jinshu surrendered to Tang. The Tang army eliminated the auxiliary forces in Jiangnan and finally dominated the world.

In 621, the Tang general Li Jing won the battle of Tang Ping and Xiao Milling, and Emperor Liang Xiao Milling surrendered to Tang in Jiangling. The following year, Lingnan Feng Ang surrendered, and Qianzhou Lin Shihong died, and the Chinese headquarters came under the ownership of the Tang Dynasty.

During the reign of Li Yuan, according to the old system of Emperor Wen of Sui, the central and local administrative systems were re-established, and the format of laws and decrees was revised, and the system of uniform land and rent was promulgated, and the government and military system were rebuilt, laying the foundation for the system of officials, criminal law, military system, land and military service in the Tang Dynasty.