Emperor Gaozong of Tang in the context of "Emperor Taizong of Tang"

Empress Zetian (624 – 16 December 705), commonly known as Wu Zetian, personal name Wu Zhao, was the empress regnant (huangdi, 皇帝) and only ruler of the (Wu) Zhou dynasty from 690 to 705. She had previously held power as the second wife and empress consort of Emperor Gaozong of the Tang dynasty from 660 to 683 and as empress dowager during the reigns of her sons Emperors Zhongzong and Ruizong of Tang between 683 and 690, holding de facto power during these periods. She was the only female sovereign in the history of China who is widely regarded as legitimate. Modern scholarship has re-examined Wu Zetian's rule beyond traditional portrayals of manipulation and cruelty. Recent studies highlight her administrative reforms, expansions of the civil-service examination system, and support of Buddhist symbolism as instruments of governance and legitimacy. During her 45 year tenure, China grew larger, its culture and economy were revitalized, and corruption in the court was reduced. She was eventually removed from power during the Shenlong Coup [zh] and died a few months later.

In early life, Empress Wu was a concubine of Emperor Taizong. After his death, she married his ninth son and successor, Emperor Gaozong, officially becoming Gaozong's empress, the highest-ranking of his consorts, in 655. Empress Wu held considerable political power even before becoming empress, and began to control the court after her appointment. After Gaozong's debilitating stroke in 660, she became administrator of the court, a position with similar authority to the emperor's, until 683. History records that she "was at the helm of the country for long years, her power no different from that of the emperor". On Emperor Gaozong's death in 683, rather than entering retirement, and not interfering in the government, Empress Wu broke with tradition and took acquisition of complete power, refusing to allow either of her sons to rule. She took the throne in 690 by officially changing the name of the dynasty from Tang to Zhou, changing the name of the imperial family from Li to Wu, and holding a formal ceremony to crown herself as emperor.

The Sasanian dynasty (also known as the Sassanids or the House of Sasan), the last Persian lineage of rulers to achieve hegemony over much of Western Asia before Islam, ruled 224 CE–650 CE. the house of Sasan founded the Sasanian Empire of Iran, It began with Ardashir I, who named the dynasty in honour of his predecessor, Sasan.

The Shahanshah was the sole regent, head of state and head of government of the empire. At times, power shifted de facto to other officials, namely the spahbed. Upon the empire's conquest by the Islamic caliphate in 651, members of the imperial family fled in exile to China following the death of Yazdegerd III, where they would become accepted as members of the imperial court by Emperor Gaozong of Tang. Although there would be numerous attempts to invade Islamic Persia with Chinese support, this branch of Sasanids would remain in China indefinitely. Narsieh, grandson of Yazdegerd and last recorded Sasanid in China, would adopt the surname Li (李) in honor of the Chinese imperial family.

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.

The Paekche–Tang War was fought between Paekche and the allied forces of the Tang dynasty and Silla between 660 and 663. The war was caused by the ongoing Goguryeo–Tang War in which numerous attacks and raids were made by Baekje and Goguryeo against Silla. King Muyeol of Silla sought help from Emperor Gaozong of Tang, who launched the invasion of Paekche in 660. After the conquest of Paekche later that year, loyalist forces from Paekche with the aid of Yamato allies attempted to resist the occupation of their kingdom until the two allied forces were destroyed in 663.

Woncheuk (Korean: 원측; MR: Wŏnch'ŭk, c. 613–696) was a Korean Buddhist monk who worked in seventh century China. Woncheuk was a follower of Paramārtha (499–569) and the Shelun school of Yogacara. This school defended the view that there was a ninth consciousness called the "pure consciousness" (amalavijñāna), as opposed to just the eight consciousnesses of classical Yogacara. This position had been rejected by Xuanzang and Kuiji. Woncheuk later became a student of Xuanzang (c. 600–664) and worked in his translation team. Woncheuk's works attempt to reconcile the two traditions of East Asian Yogacara and often diverges from the interpretations of Xuanzang and Kuiji in favor of the views of Paramārtha.

Woncheuk's work was revered throughout China and Korea, even reaching Chinese rulers like Emperors Taizong, Gaozong of Tang and Empress Wu of Zhou. Woncheuk's exegetical work also influenced Tibetan Buddhism and the greater Himalayan region.