Wu Zetian in the context of "Princess Taiping"

The Tang dynasty (/tɑːŋ/, [tʰǎŋ]; Chinese: 唐朝), or the Tang Empire, was an imperial dynasty of China that ruled from 618 to 907, with an interregnum between 690 and 705. It was preceded by the Sui dynasty and followed by the Five Dynasties and Ten Kingdoms period. Historians generally regard the Tang as a high point in Chinese civilisation, and a golden age of cosmopolitan culture. Tang territory, acquired through the military campaigns of its early rulers, rivalled that of the Han dynasty.

The Li family founded the dynasty after taking advantage of a period of Sui decline and precipitating their final collapse, in turn inaugurating a period of progress and stability in the first half of the dynasty's rule. The dynasty was formally interrupted during 690–705 when Empress Wu Zetian seized the throne, proclaiming the Wu Zhou dynasty and becoming the only legitimate Chinese empress regnant. The An Lushan rebellion (755–763) led to devastation and the decline of central authority during the latter half of the dynasty.

Zhou, known in historiography as the Wu Zhou (Chinese: 武周) and Southern Zhou (Chinese: 南周), was a short-lived Chinese imperial dynasty that existed between 690 and 705. The dynasty consisted of the reign of one empress regnant, Wu Zhao (Wu Zetian), who usurped the throne of her son, the Emperor Ruizong of Tang, in 690. The dynasty lasted until another one of Wu Zhao's sons, the Emperor Zhongzong of Tang, was restored to the throne in the Shenlong Coup [zh] in 705, marking the restoration of the Tang dynasty. Historians generally regard the Wu Zhou as an interregnum of the Tang dynasty.

Wu named her dynasty after the ancient Zhou dynasty, from whom she believed herself to be descended.

Li Chongrun (Chinese: 李重潤; pinyin: Lǐ Chóngrùn; c.2 March 682 – October 8, 701), né Li Chongzhao (Chinese: 李重照; pinyin: Lǐ Chóngzhào), formally Crown Prince Yide (Chinese: 懿德太子; pinyin: Yìdé Tàizǐ ), was an imperial prince of the Tang dynasty and Wu Zetian's Zhou dynasty. He was the only son of Emperor Zhongzong (Li Zhe/Li Xian) and Emperor Zhongzong's second wife Empress Wei. In 701, he offended his grandmother Wu Zetian by discussing Wu Zetian's lovers Zhang Yizhi and Zhang Changzong with his sister Li Xianhui the Lady Yongtai and her husband Wu Yanji (武延基) the Prince of Wei, and he, along with Li Xianhui and Wu Yanji, were forced to commit suicide. He was posthumously honored as crown prince after his father Emperor Zhongzong was restored to the throne in 705 and in 706, Emperor Zhongzong provided Li Chongrun with an honorable burial by interring his remains at the Qianling Mausoleum.

The Qian Mausoleum (Chinese: 乾陵; pinyin: Qiánlíng) is a Tang dynasty (618–907) tomb site located in Qian County, Shaanxi Province, China, and is 85 km (53 mi) northwest of Xi'an. Built in 684 (with additional construction until 706), the tombs of the mausoleum complex house the remains of various members of the House of Li, the imperial family of the Tang dynasty. This includes Emperor Gaozong (r. 649–83), as well as his wife, Wu Zetian, who assumed the Tang throne and became China's only reigning female emperor from 690 to 705. The mausoleum is renowned for its many Tang dynasty stone statues located above ground and the mural paintings adorning the subterranean walls of the tombs. Besides the main tumulus mound and underground tomb of Emperor Gaozong and Wu Zetian, there are 17 smaller attendant tombs, or peizang mu. Presently, only five of these attendant tombs have been excavated by archaeologists, three belonging to members of the imperial family, one to a chancellor, and the other to a general of the left guard. The Shaanxi Administration of Cultural Heritage declared in 2012 that no further excavations would take place for at least 50 years.

Emperor Ruizong of Tang (22 June 662 – 13 July 716), personal name Li Dan, also known at times during his life as Li Xulun, Li Lun, Wu Lun, and Wu Dan, was the fifth and ninth emperor of the Chinese Tang dynasty. He was the eighth son of Emperor Gaozong and the fourth son of Emperor Gaozong's second wife Empress Wu. He was wholly a figurehead during his first reign when he was controlled by his mother, and he was the titular and puppet ruler of the Tang Empire from 684 to 690. During his second reign after his mother's death, significant power and influence was exercised by his sister Princess Taiping.

In February 684, Li Dan's mother Empress Wu demoted his older brother Emperor Zhongzong (Li Xian) who had attempted to rule free of his mother and named him emperor (as Emperor Ruizong). Emperor Ruizong, however, was a hollow figurehead under control of his mother and had no real power, even nominally, his name was not included in the issued documents or orders. He was not even able to move freely around his private residence, let alone attend to governmental affairs. From then onwards, the Tang dynasty existed only in name and Empress Dowager Wu ruled China for over six years as quasi-emperor. Empress Wu, was comfortable about the empire being entirely under her control, decided finally to seize the throne, so in October 690 Emperor Ruizong ceded the imperial throne to his mother, who installed herself as empress regnant – the only woman in Chinese history ever to rule with this title. She issued a decree that ended the Tang dynasty and founded the Zhou dynasty. Emperor Ruizong was reduced to the position of crown prince, with the unconventional title of Huangsi (皇嗣, "imperial successor"). In the following years, Empress Wu's nephews Wu Chengsi and Wu Sansi tried to have one of them named heir to the throne, but Wu Zetian resisted these calls. Eventually, in October 698, faced with foreign invasion and dissatisfaction at home, Empress Wu accepted the suggestion of the chancellor Di Renjie and recalled the exiled Li Xian to the capital Luoyang. Soon, Li Dan offered to yield the position of crown prince to his elder brother, and Li Xian became crown prince instead.

Emperor Zhongzong of Tang (26 November 656 – 3 July 710), personal name Li Xian, and at other times Li Zhe or Wu Xian, was the fourth and seventh emperor of the Tang dynasty of China, ruling briefly in 684 and again from 705 to 710. During the first period, he did not have actual power, which was in the hands of his mother, Empress Wu Zetian and he was overthrown on her orders after opposing his mother. During his second reign, most of the power was in the hands of his consort Empress Wei.

Emperor Zhongzong was the son of Emperor Gaozong of Tang and Empress Wu (later known as Wu Zetian), and during the reign of his father, Emperor Zhongzong's mother Empress Wu, not Emperor Gaozong, was in actual control of power as empress consort and power behind the emperor. He succeeded his father in 684, But as emperor, he had no true power, and all authority remained in the firm hands of his mother, Empress Dowager Wu. His mother, however, deposed him less than two months later in favor of his younger brother Emperor Ruizong. The former emperor, demoted to a princely rank, was exiled to the provinces and placed under house arrest. Six years later, Emperor Ruizong relinquished the throne to his mother and Empress Dowager Wu officially proclaimed herself empress regnant, while Emperor Ruizong was made crown prince.

Emperor Gaozong of Tang (21 July 628 – 27 December 683), personal name Li Zhi, was the third emperor of the Chinese Tang dynasty, ruling from 649 to 683; after January 665, he handed power over the empire to his second wife Empress Wu (the future Wu Zetian), and her decrees were carried out with greater force than the decrees of Emperor Gaozong's. Emperor Gaozong was the youngest son of Emperor Taizong and Empress Zhangsun; his elder brothers were Li Chengqian and Li Tai.

Emperor Gaozong's reign saw the primacy of Empress Wu, who became the effective power behind the Tang rule. Empress Wu aided Emperor Gaozong in his rule during the later years of his reign after a series of strokes left him incapacitated. Emperor Gaozong effectively after January 665 delegated all matters of state to Empress Wu; after that the empress acted as the power behind the emperor, "hanging the curtain and listening to politics" (垂簾聼政; Chuílián tīngzhèng). Gaozong's personal illness, affection and trust of Wu led to her wielding a great deal of power in affairs of state until the end of his reign. From official histories from the later Tang Dynasty to contemporary historians, there exists a lively debate about whether Wu exerted undue influence on Gaozong, or whether they were equal partners in the government. Empress Wu was partially in control of power from November 660 and then totally from January 665 to December 683; there was an equality of power between Gaozong and Wu, which caused them to be called "two saints" (二聖; Er Sheng, literally two emperors) both inside and outside. After Emperor Gaozong died in December 683, power fell completely and solely into the hands of Empress Wu, acting as Empress Dowager-regent, "presiding over court and issuing edicts" (臨朝稱制; lin chao chengzhi); she subsequently became the only empress regnant in Chinese history. After his death, he was interred at the Qian Mausoleum along with Wu Zetian.