Korean currency
In 1902, won was introduced as the official currency unit replacing yang at 1 won = 5 yang. The bank of Korea was established 1909 but soon after in 1910, Imperial Japan annexed Korean Empire. Under Colonial rule, the country was made to use the currency unit "yen" in the name of Korean yen, which took over the Korean won at par. After the division of Korea, the state of South Korea was established and recognized in 1948, and won was again made the official currency of the new state. "jeon" was made the subunit of the currency that divided it into 100 equal parts. Bank of Joseon issued the currency for independent South Korea for the first time that too in banknotes only.
South Korean won
On February 27, 1980, efforts were initiated to lead to a floating exchange rate. The won was finally allowed to float on December 24, 1997, when an agreement was signed with the International Monetary Fund. Shortly after, the won was devalued to almost half of its value, as part of the East Asian financial crisis.