The Bank of Japan was established in 1882, when the Finance Minister, Masayoshi Matsukata, believed that the best way to stabilise Japan's currency was to establish a central bank with the sole right to issue fully convertible banknotes, that is, notes that can be exchanged for their value in precious metal such as gold or silver. However, the first notes that were issued by the new Bank of Japan were not fully convertible. From 1885 they were only convertible into silver coins.The falling price of silver worldwide in the 1890s pushed Japan to follow the gold standard. This meant that all Japanese currency would be valued at fixed quantities of gold. A new Currency Law was formulated in 1897 in order to bring the Japanese currency into the gold standard. It stipulated that one yen, the basic unit of the new currency system of Japan, would be worth 750 milligrammes of pure gold.This 20 yen coin is one of the new denominations that were issued as Japan joined the gold standard. Two other gold coins were issued: the 10 yen and 5 yen coins, as well as six smaller denominations in silver, cupro-nickel and bronze. The new Currency Law of 1897 also stated that Bank of Japan notes would be convertible into the new gold coins.