Korea is a peninsula in East Asia inhabited by a single ethnic group but since 1945 divided by two separate states:
- Democratic People's Republic of Korea (DPRK), also known as North Korea
- Republic of Korea (ROK), also known as South Korea
The first unitary Korean state was the Joseon Kingdom founded in 1388 and lasted until 1897. It was a very isolated state and modernised Japan took advantage of this situation by occupying it during the First Sino-Japanese War. As a result the Korean Empire was founded in 1897, but lasted only until Japan fully annexed Korea in 1910. The Japanese stayed until their defeat in WW2 in 1945. The Japanese occupation was marked by forced Japanisation of Korean culture and forced prostitution of Korean women and girls. This era still dominates Korean-Japanese relations in present-day, but it looks like that very slowly the Japanese government is showing gradual recognition of war crimes, as far as Japanese honour allows for this.
After the Japanese capitulation in 1945 the Soviets had helped Kim il Sung to gain power in North Korea founding a Stalinist state there, while a right-wing dictature led by Syngman Rhee dominated the South. In 1950 North Korea invaded the South sparking the Korean War. The South Korean army almost collapsed until a US-led UN force came to the rescue and turned the frontline back north, almost conquering the entire Korean peninsula. The People's Republic of China, led by Mao Zedong, decided to intervene and sent more than a million Chinese soldiers of the National Liberation Army to repel the capitalists. At the cost of many Chinese lives Mao succeeded in bringing the frontline back to where the war started in 1950. In 1953 a stalemate was ended with a truce fixing the border where it is today, but no peace treaty was never concluded and both Koreas still face each other today at a heavily guarded border.
North Korea developed into a stalinist isolationist hereditary dictature. Kim Il Sung's son Kim Yong Il succeeded his father after his death in 1994. In 2008 Kim Yong Un succeeded his father Kim Yong Il. The current situation in North Korea reminds Chinese of the 1960's. Despite signs of cracks in the North Korean system the regime still stands strong today. It is not known exactly how the people live over there as it is extremely isolated and only a handful of tourists enter the country and these cannot move freely.
Meanwhile, South Korea transitioned from a right-wing authoritarian state into a modern industrial democracy. Companies such as Daewoo and Samsung have been able to compete globally while standards of living have improved dramatically. Its current issues are still the difficult relationship with the North, the potential cost of a reunification and the aging of the population which can bring economic growth under downward pressure.
Currency
Joseon area coinage resembled that of China and Japan. Cash coins were denominated in Mun (compare Japanese Mon). Only in 1892 a modern currency based on the Chinese Tael developed. This Korean Yang was worth 1000 Mun, 100 Fun/Pun or 10 Jeon/Chon.
In 1902 the Won replaced the Yang at 5 Yang per Won. The Won was at par with the Japanese Yen of those days, which was worth $0.50.
Between 1910 and 1945 the Korean Yen circulated in banknote form, where Japanese coins were used in Korea as well. After WW2 both the North Korean Won and South Korean Won replaced the Yen at par.
The First South Korean Won was worth 15₩/$ in 1945, but a series of devaluations due to the Korean War moved the exchange rate to 6000₩/$ in 1951. The Hwan replaced the Won in 1953 at a rate of 100 to 1. The Hwan saw the first South Korean coins minted in 1958. This currency also suffered from inflation with the exchange moving from 60 Hwan/$ in 1953 to 1250 Hwan/$ in 1962, after which the Second Won replaced the Hwan at a rate of 10 to 1.
The Second Won stabilised but still depreciated. In 1972 the exchange rare reached 400₩/$. From 1980 it has been a floating currency with the current exchange rate around 1000 ₩/$. Most of the drop happened during the 1997 Asian financial crisis.
In North Korea the free market was abolished and domestic currency was only used for buying basic necessities and did not function as a currency as in capitalist economies. For foreigners, foreign exchange certificates were issued in red and blue depending whether the visitor was from a socialist or capitalist country. After 1999 visitors can pay in hard currency directly at rates that look rather ridiculous compared to black market rates.
The North Korean Won was revalued in 2009 at a rate of 100 to 1. This revaluation was performed in the classic communist way by limiting the amount of currency to be converted and hence taking people's savings. This resulted in protests after which some civilians are reported to have been executed.
Coins
Coins from unified Korea are very hard to find. I have only rarely seen any up for auction in the past years, but maybe it's easier to find them in Korea itself.
North Korean coins from 1959 were marked with dots depending on whether the coin was for use by socialist or capitalist visitors. Domestic coinage had no dots. In the communist tradition almost all coins are made of aluminium. There are also many official and unofficial non-circulating commemoratives.
https://en.numista.com/catalogue/korea-1.html
https://en.numista.com/catalogue/coree_du_nord-1.html
https://en.numista.com/catalogue/coree_du_sud-1.html