Zhou, known in historiography as the Northern Zhou, was a Xianbei-led dynasty of China that lasted from 557 to 581. One of the Northern dynasties of China's Northern and Southern dynasties period, it succeeded the Western Wei dynasty and was eventually overthrown by the Sui dynasty.

Emperor Xuan of Northern Zhou (北周宣帝), personal name Yuwen Yun (宇文贇), courtesy name Qianbo (乾伯), was an emperor of the Xianbei-led Northern Zhou dynasty of China. He was known in history as an erratic and wasteful ruler, whose actions greatly weakened the Northern Zhou regime. As part of that erratic behavior, he passed the throne to his son Emperor Jing in 579, less than a year after taking the throne, and subsequently entitled not only his wife Yang Lihua empress, but four additional concubines as empresses. After his death in 580, the government was taken over by his father-in-law Yang Jian, who soon deposed his son Emperor Jing, ending the Northern Zhou and establishing the Sui dynasty.