King Zhou (Chinese: 紂王; pinyin: Zhòu Wáng) was the pejorative posthumous name given to Di Xin (Chinese: 帝辛; pinyin: Dì Xīn), the last king of the Shang dynasty of ancient China. He is also called Zhou Xin (紂辛; Zhòu Xīn). He may also be referred to by adding "Shang" (商 Shāng) in front of any of his names. In Chinese, 紂 also refers to a horse crupper, the part of a saddle or harness that is most likely to be soiled by the horse.
In the Records of the Grand Historian, Sima Qian wrote that Di Xin, in the early part of his reign, had abilities which surpassed those of the ordinary man, and was quick-witted and quick-tempered. According to legend, he was intelligent enough to win all of his arguments, and he was strong enough to hunt wild beasts with his bare hands. He was the younger brother of Wei Zi and Wei Zhong and father of Wu Geng. His father Di Yi had two brothers, Ji Zi and Bi Gan. Di Xin added to the territory of Shang by battling the tribes surrounding it, including the Dongyi to the east.