Wǔ Zétiān 武則天 (b. 624, r. 690–705 as emperor of the Wǔ Zhōu 武周 dynasty, d. 705), personal name Wǔ Zhào 武曌 (the character 曌 a sui-generis coinage of her own, “[Sun and Moon over] Sky,” symbolising her cosmic-imperial pretensions), was the only woman in Chinese history to assume the imperial title in her own right. Native of Wénshuǐ 文水 in Bīngzhōu 並州 (modern Shānxī). She entered the Táng harem of Tàizōng 太宗 as a cáirén 才人 (junior consort), survived the death of Tàizōng (649) by being briefly tonsured at the Gǎnyèsì 感業寺, was recalled by Tàizōng’s son Gāozōng 高宗 (r. 649–683), rose to the position of empress-consort (huánghòu 皇后) in 655, became de facto co-ruler with Gāozōng from his stroke in 660, was huánghòu and then Tiānhòu 天后 of his last decades, and after his death in 683 successively deposed her own sons Zhōngzōng (r. 683–684, 705–710) and Ruìzōng (r. 684–690 and 710–712), elevating herself in 690 as Shènshén Huángdì 聖神皇帝 of the new Wǔ Zhōu 武周 dynasty.
Her court was the most consequential patron of Buddhist translation activity in Tang Chinese history. Her ideological self-presentation drew heavily on the Tachéng Dàyún jīng 大乘大雲經 (a Tang manipulation of an older sūtra in which Wǔ Zétiān was identified as the long-foretold female cakravartin queen) and on the Bǎo-yǔ jīng 寶雨經 (T0660, translated under her direction by Bodhiruci 菩提流志 in 693). Most famously, she sponsored the new (80-fascicle) translation of the [[KR6e0010|Huáyán jīng]] by 實叉難陀 Śikṣānanda — for which she wrote a personal preface dated 695 — and the great translation enterprises of 菩提流志 Bodhiruci and 義淨 Yìjìng. She also engaged 法藏 Fǎzàng as her court Huáyán scholar and patronised the institutional consolidation of the Huáyán school.
Her honorific titles in Buddhist contexts include Tiāncè Jīnlún Shèngshén Huángdì 天冊金輪聖神皇帝 (“Heaven-Mandated Golden-Wheel Holy Spiritual Emperor”; under this title she signs the Dàfāngguǎng fó huáyán jīng xù 大方廣佛華嚴經序 / Dà Zhōu xīn yì xù 大周新譯序). She was forced to abdicate by the Shénlóng coup of 705 and died later the same year. Her preface to the Huáyán — preserved at the head of T0279 — is one of the most stylistically accomplished imperial Buddhist prefaces in Chinese.