Korean mun

The mun was introduced as the main currency of Korea in 1625 and stayed in use until 1892. Prior to the mun, cash coins with the inscriptions tongbo and jungbo and silver vases called ŭnbyŏng were used as currency in the Goryeo Dynasty, as well as imported Chinese currency. The mun resembled and was derived from the Chinese wén. Coins denominated in mun were cast in copper-alloys such as brass or bronze and were round with square holes. From the 17th century until the end of the 19th century, coins denominated in mun bearing the inscription Sangpyeong Tongbo, introduced in 1633, were the most widely circulated currency. In 1888, coins were struck in small numbers denominated in mun and won. The mun was replaced in 1892 when the yang was introduced.
The cast coins of the mun would remain in circulation long after their abolition. They continued to be legal tender in Korea at a value of 0.1 chon until 1908, when they were revalued to 0.2 chon, or won.

History

Goryeo

The first definitive record of currency use in Korea appears in the Goryeo period. Early in that period, even though some imported Chinese currency from the Tang and Song dynasties were in circulation, commodity currency such as grain and linen continued in general circulation. In the 10th and 11th centuries, iron and bronze coins were issued, but saw limited circulation among the common people.
Around this time, the Goryeo government issued a new monetary policy regarding the minting and distribution of cash coins. This decree was implemented to both strengthen royal authority and to regulate the national finances of Korea.
King Sukjong of Goryeo created a new monetary system based on round copper-alloy coins with square holes as well as the ŭnbyŏng shaped like the Korean Peninsula. The coins were produced bearing the inscriptions , , and .
An extremely rare variant of the Samhan Tongbo cash coin exists that bears the character written in "official script" instead of, of which only 2 have currently been found.
A new government department, the Directorate of the Mint was created, this government agency was in charge of regulating the newly established currency system, and the Dongguk Tongbo was the first of these new Korean cash coins to be minted.
In order to strengthen the monetary policy of Goryeo, government officials were encouraged to receive their salaries in cash coins and it was hoped that if they would spend the new currency at local taverns that this would encourage their circulation to become widespread throughout Korea. However, the new cash coin's value would prove to be rather unreliable in the marketplace and it was considered to be impractical for purchasing and trading goods. Because of this perception the new cash coins of Goryeo did not find wide usage.
The ŭnbyŏng silver vases were widely used and circulated among the aristocracy. These ŭnbyŏng were produced from the year 1101 and were engraved with an official state seal to mark them as a legitimate currency which was valid throughout Goryeo. The ŭnbyŏng weighed around one Kŭn which is roughly equal to 600 grams, this made them very useful for paying for large transactions. Historians suggest that the ŭnbyŏng primarily used by the aristocratic classes and that were also often involved in the bribing of government officials. In the year 1282 the government enacted a law that pegged the value of one ŭnbyŏng at between 2,700 and 3,400 litres of rice. But regardless of the fact that this currency was highly impractical for paying for low value items, the ŭnbyŏng would continue to be used during the next two centuries.
During the reign of Chungnyeol of Goryeo the government had permitted the circulation of rough or broken pieces of silver. By the year 1331 the ŭnbyŏng had completely disappeared from circulation. No specimens of the ŭnbyŏng are known to have survived to the modern era.

Inscription	Hangul	McCune–Reischauer	Revised Romanisation	Scripts	Date of casting	Diameter	Weight	Image
東國通寶	동국통보	Dong kuk T'ong Bo	Dong Guk Tong Bo	Seal script, Clerical script, Regular script, and Running script	998–1097 AD	23 ~ 25	2.4 ~ 3
東國重寶	동국중보	Dong Kuk Chung Bo	Dong Guk Jung Bo	Regular script	998–1097 AD	24 ~ 25	2.8 ~ 3.6
三韓通寶	삼한통보	Sam Han T'ong Bo	Sam Han Tong Bo	Seal script, Clerical script and Running script	1097–1105 AD	23 ~ 25	2.6 ~ 3.4
叁韓通寶	삼한통보	Sam Han T'ong Bo	Sam Han Tong Bo	"Official Script"	1097–1105 AD
三韓重寶	삼한중보	Sam Han Chung Bo	Sam Han Jung Bo	Regular script	1097–1105 AD	25	4
海東通寶	해동통보	Hae Dong T'ong Bo	Hae Dong Tong Bo	Seal script, Clerical script, Regular script, and Running script	1097–1105 AD	25	2.9
海東重寶	해동중보	Hae Dong Chung Bo	Hae Dong Jung Bo	Regular script	1097–1105 AD	25	3.1 ~ 4
海東元寶	해동원보	Hae Dong Wŏn Bo	Hae Dong Won Bo	Regular script	1097–1105 AD

Joseon

''Joseon Tongbo'' and ''Shibjeon Tongbo'' cash coins

It was not until the beginning of the Joseon period that copper coins were minted for wide circulation.
The Jeohwa, which was made of standardized mulberry-bark paper early in the Joseon period, became the first legal paper money in Korea and was used as a medium of exchange in place of coins until it disappeared in the early 16th century. Korean traders at the time also accepted the Chinese Great Ming Treasure Note banknotes. However, banknotes were almost exclusively used for the payment of taxes, and they struggled to catch on in the general Korean market. No paper money survives from this period.
During the early years of the Joseon period cloth and grains would remain the most common forms of currency among the Korean people, during this time cotton was considered to be the most important medium of exchange. The government of Joseon also recognised the prominent role that cotton played in the Korean economy and the highest quality specimens of cotton would be stamped with the text "Joseon Tongpyejiin", which could be seen as a government seal of approval and meant that it could be used as currency throughout Korea. Barter would remain the norm in Joseon society for many generations before the reintroduction of cash coinage.
Bronze coins were cast starting in 1423 during the reign of king Sejong the Great with the Joseon Tongbo cash coins. The coins produced under Sejong were pegged to copper at 160 coins to one Kŭn which is equal to 600 grams, though the actual market rates regularly fluctuated. But the monetary system proved to be unpopular as people resorted back to barter after a few years.
The Sejong era Joseon Tongbo cash coins were only issued in the years 1423, 1424, and 1425 and all of these cash coins distinctively use the regular script font of Chinese characters which tended to be both clearly and distinctively inscribed while their reverse sides tend to be blank. This first series of Joseon Tongbo are generally about 24 millimeters in diameter and tend to weigh between 3.2 and 4 grams. These cash coins were modeled after the Chinese Tang dynasty era Kaiyuan Tongbao cash coins.
The Kings of Joseon were consistently creating new legislation aimed at promoting coins and promoted their manufacture to be widely used. Through these measures, the monarchs hoped to dispel the general mistrust that the Korean people had towards coinage and they also hoped that these decrees would boost the value of Korean cash coins.
Following the Japanese invasions of Korea it had become more necessary for there to be circulating coinage in Korea, this was needed in order to both procure military supplies and secure the national finances.
In 1625 under the reign of king Injo of Joseon a new series of cash coins with the same inscription as under Sejong the Great were minted. In order to promote the circulation of the new coinage, King Injo tried to rent out vacant rooms for the opening of new restaurants which would accept these cash coins, these rooms were situated in front of Gyeongbok Palace. This was an attempt to encourage the circulation of the new coinage and the King hoped to open the eyes of the Korean people to the value of using coinage over barter.
The government soon enacted new national laws to stimulate the usage of coinage, for instance a law that allowed for people to pay their taxes using coins. Government officials were now also required to use cash coins to pay for their expenses when they would travel as a means to help promote their circulation. Another factor that led to the more widely adoption of coinage by the Korean people this time around was the fact seasonal problems such as droughts or less productive harvests made it more difficult to manufacture grains and cloth causing them to decrease in circulation.
The second series of the Joseon Tongbo came roughly two centuries after the first and the first issues were made in the year 1625, these cash coins had their inscriptions written in "official style" script or palbun. During this era the government wasn't the only manufacturer as private minting was allowed to take place and as such these cash coins tend to be very diverse.
The second series of Joseon Tongbo cash coins tend to have a rather yellow-brown colour and the Hanja characters depicted on them were not very standardised. The character strokes can be either thin or thick and either small or large. Some varieties of this series have broad rims while others tend to have very narrow rims. Unlike with the first series of the Joseon Tongbo cash coins, Joseon Tongbo cash coins with inscriptions written using the clerical script typeface are much more scarce.
In the year 1651, King Hyojong issued a royal decree which ordered the people of Joseon to use the Joseon Tongbo cash coins and it also prohibited the usage of cloth as a currency. During this era the private production of cash coins was also allowed.
A sudden and major increase in agricultural production during the reign of King Sukjong paved the way for the opening of about 1,000 markets across Korea, this led to the development of commerce and industry in the country which in turn gave a more favourable market for the circulation of coinage. The brisk production of goods to be traded and the subsequent development of commerce led to there being a relatively stable currency system during this era. These new markets and the merchants that they brought with them substantially raised the importance of currency, cash coins were now highly valued due to their ease of transportation and storage.
This second series of Joseon Tongbo coins became the inspiration for the following Sangpyeong Tongbo series, though later these coins would be suspended due to the Later Jin, and the Qing invasions of Joseon. After those wars Korea would become dependent on importing copper from Japan in order to sustain the production of coinage.
A number of different 10 mun and 1 jeon versions of the Joseon Tongbo cash coins were also created around the year 1881, these cash coins were experimental and therefore quite rare and not many contemporary records were written about them. These cash coins tend to have a diameter of 45 millimetres and tend to weigh around 30 grams and according to some reports they were 48.2 millimetres in diameter and had a weight of 29 grams. Some of them have blank reverse sides, these can be found in two different types which is dependent on whether the Chinese characters on the obverse side are written in a "small script" or a "large script", while others have the Hanja character "十" located right above the square centre hole on the back.
The Joseon Tongbo cash coins with the denomination of 1 jeon were also only minted as an experimental issue and tend to have the mint mark of the Joseon Treasury Department on their reverse right above the square centre hole, this character was usually depicted as "戸", but can also sometimes be found as "户". On the right side of the square centre hole were the Chinese characters "一錢", indicating its nominal value. The 1 jeon Joseon Tongbo cash coins was possibly 47.6 millimeters in diameter and allegedly had a weight of 31 grams.
During the time when the 1 jeon Joseon Tongbo cash coins were issued 400 mun were valued as being worth 1 tael of silver. So in the new system planned for these Joseon Tongbo cash coins one coin of 1 jeon would have been worth forty coins of 10 mun and were themselves of a tael.
Other variants of the 1 jeon Joseon Tongbo cash coins can have some slight variations in the method that the "head" of the Chinese character Tong is written. Furthermore, there can be variations in how the Chinese character Seon is written as well, there can be slight differences in the way that the 4 bottom strokes of the "魚" are written as well as the method that the top part of the "羊" is inscribed.
Another cash coin attributed to this period is the Shibjeon Tongbo, which has been attributed by some numismatists to private mints during the reign of King Hyojong around the year 1651, while other numismatists think that the Shibjeon Tongbo cash coins may have been cast starting in 1793 under King Jeongjo. It is generally believed that the Shibjeon Tongbo is a series of privately issued cash coins which is supported by the extreme diversity between specimens.

Inscription	Hangul	McCune–Reischauer	Revised Romanisation	Date of introduction	Scripts	Diameter	Weight	Image
朝鮮通寶	조선통보	Chosŏn T'ong Bo	Joseon Tong Bo	1423, 1625	Regular script "official style"	24 ~ 24.5 45	3.2 ~ 4 30
十錢通寶	십전통보	Sip Chŏn T'ong Bo	Shib Jeon Tong Bo	1651 or 1793	Various	28 ~ 40