The Zhou Dynasty was the longest reigning dynasty in the history of China stretching from 1046 to 256BC comprising Western Zhou period (1046 to 771BC) and Eastern Zhou period (771 to 256BC). The Eastern Zhou period can be subdivided into the Spring and Autumn period (771 to 481BC) and the Warring States period (481 to 221BC). Bronze metallurgy reached its apex during this period as can be seen from the numerous beautiful bronzewares discovered. Some of the most unusual and interesting looking bronze medium of exchange in the shapes of knife and farming implement were also attributed to this period. It has the distinction of minting China's first round coins!