In 9 AD, an usurper named Wang Mang came to power for a short time in China. Wang introduced many reforms, most of them to secure his power. At the same time, however, he tried to reerect the "ideal" state, which in Wangs opinion had existed during the period of the Zhou (1045-221 BC). For Wang, this meant among other things the reintroduction of the old spade and knife currency. This coin, often described as knife or key money, dates from the reign of Wang Mang. The coin merged the old with the new: its lower part looks like an old Zhou knife coin, while the upper part was made like the Chinese round coins. It was of pretty high value, as it was worth 5000 round coins.