Wu Zetian (simplified Chinese: 武则天; traditional Chinese: 武則天; pinyin: Wǔ Zétiān (c.625 – 705) (who was also known as Wu Zhao, Wu Chao, Wu-hou, Wu Hou (Chinese: 武后; pinyin: Wǔ Hòu), in Tang Dynasty as Tian Hou (天后), Dynasty), in English as Empress Consort Wu, or by the deprecated term "Empress Wu") was a Chinese sovereign, who ruled officially under the name of her self-proclaimed "Zhou Dynasty", from 690 to 705; however, she had previous imperial positions under both Emperor Taizong of Tang and his son Emperor Gaozong of Tang, of the Tang Dynasty of China. Wu was a concubine of Emperor Taizong; after his death she married his successor and 9th son, Emperor Gaozong, officially becoming Gaozong's furen (variously translated as "empress", "wife", or "first consort") in 655, although having considerable political power previous to this. After Gaozong's debilitating stroke in 660, Wu Zetian ruled as effective sovereign until 705.
The importance to history of Wu Zetian's period of political and military leadership includes major expansion of the Chinese empire, extending it far beyond its previous territorial limits, deep into Central Asia, and completing the conquest of Korea. Within China, besides the more direct consequences of her struggle to gain and maintain supreme power, Wu's leadership resulted in important effects in regards to social class in Chinese society and in relation to state support for Taoism, Buddhism, education, and literature. Wu Zetian also had a monumental impact in regard to the statuary of the Longmen Grottoes and the "Wordless Stella" at the Qianling Mausoleum, as well as the construction of some major buildings and bronze castings which no longer survive. Despite these important aspects of her reign, together with the suggestions of modern scholarship as to the long-term effects of some of her innovations in governance, much of the attention to Wu Zetian has been to her gender, as the anomalous female supreme sovereign of a unified Chinese empire, holding during part of her lifetime the title of Huangdi.