The Zhou dynasty (1046 BC to approximately 256 BC) is the longest-lasting dynasty in Chinese history. By the end of the 2nd millennium BC, the Zhou dynasty began to emerge in the Yellow River valley, overrunning the territory of the Shang. The Zhou appeared to have begun their rule under a semi-feudal system. The Zhou lived west of the Shang, and the Zhou leader was appointed Western Protector by the Shang. The ruler of the Zhou, King Wu, with the assistance of his brother, the Duke of Zhou, as regent, managed to defeat the Shang at the Battle of Muye.