Wu Zetian, the Concubine who became an Empress
Wu Zetian was born in 624 China to a wealthy family, in which was allowed to receive an education, a rare gift at the time where it was deemed useless to develop the minds of women. When she reached the age of fourteen, she was chosen to become a low-ranked imperial concubine to the Emperor Taizong of Tang. The emperor was not particularly fond of Wu; they interacted very little, and Wu occupied herself with clerical duties.
Taizong died in 649 and was succeeded by his ninth son, Goozong. Not unlike how in the Dothraki tradition a Khaleesi must move to Vaes Dothrak when the Khal dies, after the death of a Chinese emperor, the consorts who had not given him any children were expected to leave the public eye and lead a monastic life. Therefore, as was the custom, Wu became a buddhist nun.
However, when she was visited by Taizong’s successor, emperor Gaozong, Wu charmed him so completely that she left nunnery to become his concubine. Wu became the emperor's favorite, which grew her influence tenfold. She and Gaozong got married, and she became Empress. Her husband often suffered debilitating illnesses that prevented him from enacting his duties as emperor, so Wu frequently took over his responsibilities. When her husband died, Wu dethroned Gaozong’s successor (her own son), and became Empress Dowager, Cersei-style. Then, “eight hundred common people and six thousand monks, priests, officials, and imperial relatives petitionned for her to become emperor” (Qingyn Wu) As if that wasn’t badass enough, “to consolidate her power, she found a theoretical basis in Buddhism for a woman to rule the world”. Wu became known for giving "attention to women’s religious status, welfare, education, and access to public offices”.
Wu Zetian was unmerciful toward her enemies; in Rejected Princesses, Jason Porath discusses Wu’s use of “the most hardcore use of an anonymous comment box in history”, whose “ostensible purpose was to help root out corruption, in practice, it became a repository for tattle-tale letters, often put there by her spies and secret police. Those who displeased her would inevitably be ratted out by the comment box, and be put to the sword — usually their own.”
The empress did not remarry, but had a number of affairs, including with a tempestuous buddhist monk when she was well into her sixties. When she reached her seventies, in poor health, Wu yielded the throne renounced the emperorship and died.
Jason Porath's "Rejected Princesses: Wu Zetian"