 Wu Zhu cash coins were cast from 118 BC to 618 AD having a span of 736 years, which is the longest for any coin in the history of the world.The Tang dynasty introduced the Kaiyuan Tongbao, which would influence the inscriptions of cash coins, both inside and outside of China, minted from this period onwards.The Koreans, Japanese, Ryukyuans, and Vietnamese all cast their own copper cash in the latter part of the second millennium similar to those used by China.