East Asian monetary history is closely linked to that of China. The Chinese monetary system was used as a model by neighbouring countries. Starting from the 7th century before the Common Era, China used various coinages made out of bronze. Because their exchange value exceeded the metallic value, this was an early invention of a fiduciary coinage made for circulation and not for hoarding. From the first to the last emperor, Chinese coins shared the same shape. They are round coins with a centred hole. These cash coins circulated with traders throughout East Asia. Japan first then Vietnam and finally Korea, imitated them to produce their own coinage.