Dugu sisters

The Dugu sisters were part-Xianbei, part-Han sisters of the Dugu clan who lived in the Western Wei (535–557), Northern Zhou (557–581) and Sui (581–618) dynasties of China. All were daughters of the Western Wei general Dugu Xin. The eldest sister became a Northern Zhou empress, the seventh sister became a Sui dynasty empress, and the fourth sister was posthumously honored as empress of the Tang dynasty (618–907). The seventh sister Dugu Qieluo, in particular, was one of the most influential women in ancient Chinese history, owing to her closeness to her husband Emperor Wen of Sui, throughout their 45-year monogamous marriage. Some authors have written that the three sisters "married emperors"^[1] or "married into imperial families".^[2] However, at the time of their marriages, none of their husbands were members of an imperial family (yet): each of the three sisters became an empress or a posthumous empress after a dynastic change. Out of the three dynastic transitions, only the first — the usurpation of the Western Wei throne by the Yuwens — is considered a long time coming, in which the Dugus played no role. In both Yang Jian's^[3] and Li Yuan's (Emperor Gaozu of Tang) rise to power, family ties to the ruling house (through the sisters and Dugu Qieluo's daughter Yang Lihua) were important.^[4]