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.
Economy of North Korea
In 1979, North Korea renegotiated much of its international debt, but in 1980 it defaulted on its loans except those from Japan. By the end of 1986, hard-currency debt had reached more than US$1 billion. It also owed nearly $2 billion to communist creditors, principally the Soviet Union. The Japanese declared North Korea in default. By 2000, taking into account penalties and accrued interest, North Korea's debt was estimated at $10–12 billion. By 2012, North Korea's external debt had grown to an estimated US$20 billion despite Russia reportedly writing off about $8 billion of debt in exchange for participation in natural resources development. Besides Russia, major creditors included Hungary, the Czech Republic and Iran.