Historians regard the Tang Dynasty as a high point in Chinese civilization. From its establishment by Li Yuan in AD618 to its downfall in 907, the Tang dynasty, which lasted for 289 years, was a golden age of cosmopolitan culture and it was also the most prosperous dynasty in the history of feudal China.
Chinese culture was at its most sophisticated peak. With the reopening and regaining of importance of the Silk Road in 639, trade was encouraged and new economic and trading ties with different regions were established. The influx of traders brought about an unprecedented "internationalization" of Chinese Society because traders and travelers alike brought new ideas, religions, food, music and artistic traditions into China. Buddhism flourished and Islam was introduced. Li Bai and Du Fu, the greatest poets in China's literal history lived produced their most famous works during the Tang dynasty.
(left - right) Tang Taizong and Tang Xuanzong
The Tang dynasty can be divided into the early period, which was a golden age and the late period, which was one of decline with the An Shi rebellion as its turning point. The golden age consisted of the reigns of Emperor Taizong(AD 627 - 649) and Emperor Xuanzong (AD712 - 755); the Taizong Era was known as the Flourishing Age and was the world leader in politics, economy and culture. The Xuanzong era was known as the Golden Age and it was a peaceful period. However, in the late years of Emperor Xuanzong's reign, the An Shi rebellion threw the Tang Empire into turmoil and it marked the start of its decline.
AD 626: The Xuan Wu Gate Incident
After Li Yuan (Emperor Gaozu) unified the whole of China, there was a political dispute within the imperial family between Prince Li Jiancheng and Li Shimin (who later became Tang Taizong, one of the greatest emperors in Chinese history) about who should become the heir to the throne.
Li Jiancheng was the eldest and Li Shimin was the second eldest. According to the hereditary system, the eldest son was the rightful heir, hence he would be made Crown Prince. However, among Li Yuan's sons, Li Shimin's contributions were the biggest as he defeated four of Tang's most powerful competitors - the Emperor of Qin Xue Rengao , the Dingyang Khan Liu Wuzhou, the Prince of Xia Dou Jiande and the Emperor of Zheng Wang Shicong. Li Jiancheng was completely overshadowed by his younger brother.
As the years passed, Li Shimin made even more significant contributions and that incurred the jealousy of his brothers Li Jiancheng and Li Yuanji (Li Jiancheng and Li Shimin's younger brother) who wanted to eliminate him.
In the summer of AD626, the General Ashina Yushe of Eastern Tujue entered Tang territory and put Wucheng under siege. Under normal circumstances, Li Shimin would be sent to meet the Easter Tujue forces but at Li Jiacheng's recommendation, Emperor Gaozu sent Li Yuanji instead and the troops under Li Shimin were transferred to him. Fearful that Li Jiancheng and Li Yuanji would take the chance to go against him, Li Shimin decided to act by submitting a secret accusation to his father in the night, accusing his brothers of having affairs with his father's concubines and making plans to kill him. Emperor Gaozu then decided to summon his sons to his palace the next morning.
Xuan Wu Gate in Present day China
The next morning, Li Shimin and his brother-in-law Zhangsun Wuji went to Emperor Gaozu's palace early and secretly took command at the north gate of the palace - the infamous Xuan Wu gate. Sensing that something was amiss when they arrived, Li Jiacheng and Li Yuanji began to head back. When Li Shimin alone started chasing after them, Li Yuanji fired arrows at him and a fight erupted in front of the Xuan Wu gate, which was the most important gate to the palace.
In the end, Li Shimin killed Li Jiancheng. Then, he told his father that both his brothers had committed treason and he had executed them. Two months later, Emperor Gaozu passed the throne to Li Shimin, who ascended the throne as Emperor Taizong, becoming one of the greatest emperors that China has ever had.
AD 756 - 763: An Shi Rebellion
The An Shi Rebellion was started by rebel An Lushan and Shi Siming, spanning the reign of three Tang emperors, starting at the reign of Xuanzong and ending at the reign of Dai Zong and was instrumental in the decline of the Tang dynasty.
Although Emperor Xuanzong was credited with bringing China to the pinnacle of culture and power during the Tang Dynasty, he was preoccupied most of the time with everything (the artistic endeavors, his favorite concubine Yang Guifei) but the state affairs. Thus, he placed too much trust in incompetent ministers such as Li Linfu and Yang Guozhong and rebel An Lushan.
An Lushan was given control over the northern area of the lower reaches of the Yellow River by Emperor Xuanzong. With so much land and power under his control, he planned a revolt, taking advantage of the absence of strong troops guarding the palace and of the discontentment with the extravagant lifestyle employed by the court despite a string of natural disasters.
As An Lushan forces continued into the capital Chang'An, Emperor Xuanzong fled to Sichuan with his household. On the way, Xuanzong's bodyguard troops demanded the death of Yang Guifei, whom they viewed as the cause of the emperor's disinterest with state affairs, which was partly allowed the rebellion to take place. Left with no other choice, he ordered his beloved concubine's death. After reaching Sichuan, feeling guilty and saddened by the death of Yang Guifei, Xuanzong abdicated in favor of the Crown Prince.
Led by Emperor Suzong, the imperial forces were aided by internal conflict in the newly formed dynasty headed by An Lushan, who was killed by his son An Qingxu shortly after his ascent to the throne. An Qingxu was then killed by General Shi Siming who recaptured Luoyang soon after. However, Shi Siming was then killed by his son Shi Chaoyi. As it became clearer that the new dynasty would soon topple over, defects to the Tang army began. Shi Chaoyi committed suicide and this ended the rebellion.
Sadly, the rebellion greatly devastated the political and economical climate as well as the intellectual culture of the Tang dynasty. Many intellects had their careers interrupted, leaving them with time to ponder the causes of the unrest. Concluding that a lack of moral seriousness in intellectual culture had been the cause, they started to lose faith in themselves. More importantly, the Tang dynasty was unable to return to its glory days under Taizong and Xuanzong, existing in name only for the next hundred years.
AD 835: The Event of Dew
In the late Tang dynasty, the eunuchs controlled the court and they were so powerful that emperors were abolished as they please. While Emperor Wen Zong was on the throne, some officials devised a plan to get rid of the eunuchs. They announced that there was a pomegranate tree that was covered by dew in the palace and invited all the eunuchs to see that sight. Meanwhile, a group of soldiers hid near the tree so as to kill the eunuchs when they are near. Unfortunately, the soldiers were discovered as one eunuch approached the tree. The emperor was then held hostage. All the officials who participated in the Event of Dew were executed and the emperor was placed under house arrest until he died of depression.
AD 845: Wu Zong Great Anti Buddhist Persecution
The Great Anti Buddhist Persecution was an effort to appropriate war funds by stripping Buddhism of its financial wealth. During this period, all Buddhist clergy had their properties confiscated and were forced into lay life or hiding. Foreign influences were also driven out of China and followers of other religions such as Christianity and Islam were prosecuted. This tragedy lasted for 20 months before the next emperor, Emperor Xuanzong put forth a policy of tolerance in 846.