Wu Zetian (c. 624-705) was the only female ruler in dynastic China. She ruled for twenty-five years, fifteen as empress of the second Zhou dynasty. Her rule was controversial and has been criticized harshly by Confucian historians.
Wu Zetian entered the Tang palace at 13 and became a concubine of Emperor Taizong. After his death, she was brought back into the palace by the new Emperor Gaozong. She was his favorite, and became his new wife after Empress Wang passed. As empress Wu progressively gained more and more influence over the governance of the empire throughout Gaozong's reign. She was regarded as ruthless in her endeavors to grab power, and was believed by traditional historians to have even killed two of her own children.
After Emperor Gaozong's death in 683, Empress Wu became the Empress Dowager. She ruled through her sons until 690, when she declared that she was the new emperor. She ruled until she died in 705.
As a ruler
Wu Zetian promoted Buddhism over other philosophies and had Buddhas carved in her own image. She used secret police to persecute her enemies for most of her reign, including relatives. After she took the throne, she became known for spending all her time with her many lovers, most of them palace servants and maids.
The traditional Chinese historical view on her was generally mixed. Traditional Confucian historians view her as brutal and corrupt. She is viewed in a better light by many modern historians and especially feminist scholars.
Empress Wu tried to change several Chinese characters. The alternate characters are not used today. However, scholars of women's history use them sometimes out of respect for Wu Zetian.
There is a stele to Empress Wu at the Qianling Mausoleum. Usually, the stele is covered with characters that describe the Emperor's achievements. Empress Wu's stele is blank. The empress ordered that it be unmarked so that a future generation could carve her legacy onto it.