The Zhou dynasty (1122-256 B.C.E), began as a simple tribe during the Shang dynasty. As the Shang Empire lost power, the Zhou tribe only grew larger and stronger. After increasing hostilities between the two groups, Wuwang and the Zhou tribe over threw the Shang Empire, thus was the end of the Shang Empire and the start of the Zhou Empire. The Zhou dynasty was really the start of iron working in China and a mercantilism society as opposed to the Shang and Xia who greatly relied on solely agriculture to fuel their empires.