The won (code: KRW) is the currency of South Korea. A single won is divided into 100 jeon, the monetary subunit. The jeon is not used anymore for everyday transactions, and appear only on foreign exchange rates. The South Korean won is a major currency in Asia along with the Japanese yen, Singapore dollar, and Hong Kong dollar.

The won was first used as Korea's currency between 1902 and 1910. After the Japanese invasion and subsequent occupation, the won was replaced at par by the yen, made up of the Japanese currency and banknotes of the Korean yen.

In 1945 after World War II, Korea became divided, resulting in separate currencies, both called won, for the South and the North. Both the Southern won and the Northern won replaced the yen at par. The first South Korean won was subdivided into 100 jeon. Only banknotes were issued, which initially circulated alongside banknotes of both the Japanese and Korean yen and Japanese coins.

The South Korean won was initially pegged to the U.S. dollar at a rate of 15 won = 1 dollar. A series of devaluations followed, the later ones in part due to the Korean war.

In 1946, the Bank of Joseon introduced 10 and 100 won notes. These were followed in 1949 by 5 and 1000 won notes. The designs were similar to those of the yen notes from the Japanese occupation period. However, there were two subtle and important differences. The new notes replaced the paulownia, the badge of the government of Japan, with the five-petalled Rose of Sharon, South Korea's national flower. The clause referring to exchangeability with the Japanese yen was also removed.

A new central bank, the Bank of Korea, was established in 1950, and assumed the duties of Bank of Joseon. Notes were introduced (some dated 1949) in denominations of 5, 10 and 50 jeon, 100 and 1000 won. 500 won notes were introduced in 1952. In 1953, a series of banknotes was issued which, although it gave the denominations in English in won, were, in fact, the first issues of the hwan.

In 1968, as the intrinsic value of the brass 1 won coin far surpassed its face value, new aluminium 1 won coins were issued to replace them. As an attempt to further reduce currency production costs, new 5 won and 10 won coins were issued in 1970, struck in brass. Cupro-nickel 100 won coins were also introduced that year, followed by Cupro-nickel 50 won in 1972.

In 1982, with inflation and the increasing popularity of vending machines, 500 won coins were introduced on June 12, 1982. In January 1983, with the purpose of standardizing the coinage, a new series of 1, 5, 10, 50, and 100 won coins were issued, using the same layout as the 500 won coins, but conserving the coins old themes.

In 1965, 100 won notes (Series III) were printed using intaglio printing techniques, for the first time on domestically printed notes, to reduce counterfeiting. Replacements for the British 500 won notes followed in 1966 also using intaglio printing, and for the 50 won notes in 1969 using litho-printing.

With the economic development from the 60s the value of the 500 won notes became lower, resulting in a greater use of cashier's checks with higher fixed denominations as means of payment, as well as an increased use of counterfeited ones. In 1970, the 100 won notes were replaced by coins, with the same happening to the 50 won notes in 1972.

Higher denomination notes of 5000 won and 10,000 won were introduced in 1972 and 1973 respectively. The notes incorporated new security features, including watermark, security thread and ultraviolet response fibres and were inglio printed. The release of 10,000 won notes was planned to be at the same time as the 5000 won notes but problems with the main theme delayed it by a year. Newly designed 500 won notes were also released in 1973 and the need for a medium denomination resulted in the introduction of 1000 won notes in 1975.

In 1982, the 500 won note was replaced by a coin. The following year, as part of its policy of rationalizing the currency system, the Bank of Korea issued a new set of notes, as well as a new set of coins (see above). Some of the note's most notable features were distinguishable marks for the blind under the watermark and the addition of machine-readable language in preparation for mechanization of cash handling. They were also printed on better quality cotton pulp to reduce the production costs by extending their circulation life.

In 2006, it became a major concern that the Korean won banknotes were being counterfeited/forged. Notably the 5000 won note (worth about US$5), over 50% of the notes were confiscated as counterfeit. This led the government to issue a new series of banknotes, with the 5000 won note being the first one to be redesigned. Later in 2007, the 1000 and the 10000 won note was introduced.

South Korea boasts one of the most advanced security features on their banknotes, with over 10 security features in each denomination of banknote. The 10000 won note has 21 security features, the 5000 won note with 17, and the 1000 won note with 19 security features. Many modern security features that can be also found in Euros, British Pounds, Canadian Dollar, Japanese Yen are included in the banknotes.

The leu ([lew], plural: lei [lej]; ISO 4217 code RON; numeric code 946) is the currency of Romania. It is subdivided into 100 bani (singular: ban). On 1 July 2005, Romania underwent a currency reform, switching from the previous leu (ROL) to a new leu (RON). 1 RON is equal to 10,000 ROL.

Romania joined the European Union on 1 January 2007 and it is expected to adopt the euro in 2014.

On August 15, 1947, a revaluation took place, with a new leu replacing the old one at a rate of 20,000 old lei = 1 new leu. This revaluation, called a monetary reform or stabilisation measure (mica stabilizare, marea stabilizare), was carried out by the Communist authorities with absolutely no advance warning and without the possibility to exchange more than a fixed amount of money for the new currency. This was done in order to depose the former middle and upper classes of their last assets, after nationalization, to prepare for collectivization and to finalize the installation of communism. At the time of its introduction, 150 new lei equalled 1 U.S. dollar.

In the 1990s, after the downfall of communism, inflation ran high due to reform failures, the legalization of owning foreign currency in 1990, and the bankrupt policies of the former communist era, reaching rates as high as 300% per year in 1993. By September 2003, one euro was exchanged for more than 40,000 lei, this being its peak value. Following a number of successful monetary policies in the late 1990s and early 2000s, the situation became gradually more stable, with one digit inflation in 2005.

The Romanian leu briefly held the dubious distinction of being the world's least valued currency unit, from January (when the Turkish lira dropped six zeros) to July 2005. However, the 1,000,000 lei bill was not the highest Romanian denomination ever. This distinction belongs to the 5 million lei bill from 1947.

On 1 July 2005, the leu was revalued at the rate of 10,000 "old" lei (ROL) for one "new" leu (RON), thus psychologically bringing the purchasing power of the leu back in line with those of other major Western currencies. The term chosen for the action was "denominare", similar to the English "denomination", to signify not a conversion, but rather a total reinvention.

The first day brought difficulties adjusting to the new paper currencies and closed ATMs (that needed reprogramming) and forcing a new calculation habit that slowed down shops and annoyed some salespeople and shoppers. The old ROL currency banknotes remained in circulation until December 31, 2006 (coins remained in circulation only until December 31, 2005), but all accounts have been converted starting July 1, 2005. There is no conversion time limit between the currencies. Retailers had to display prices in both old and new currency from March 1, 2005 until June 30, 2006. The appreciation of the leu during 2005 was about 20% against a basket of major currencies.

As of 2006, the revaluation is a potential source of confusion, especially to visitors, since both old and new currency values are commonly quoted. When written, the very large amounts in old currency are usually obvious, but in speaking inhabitants might refer to an amount of 5 new lei as simply "fifty" in reference to its value 50,000 old lei.

In 1952, coins were introduced in denominations of 1, 3, 5, 10 and 25 bani, with the 1, 3 and 5 struck in aluminium bronze and the others in cupro-nickel. In 1955, cupro-nickel 50 bani were added.

In 1960, a new coinage was introduced, consisting of 15 and 25 bani, with 5 bani, 1 and 3 lei coins added in 1963. All were struck in nickel-clad steel. In 1975, aluminium replaced steel in the 5 and 15 bani, with the same change happening for the 25 bani in 1982. Aluminium 5 lei were introduced in 1978.

Following the end of the communist regime, a new coinage was introduced between 1990 and 1992, consisting of 1 leu in bronze clad steel, 5 and 10 lei in nickel plated steel, 20 and 50 lei in brass clad steel and nickel plated steel 100 lei.

As inflation took its toll, 500, 1000 and 5000 lei coins were introduced in 1999, 2000 and 2001, respectively, and were the only coins circulating when the revaluation occurred. They were all criticized for being clumsy and difficult to use. The 500 lei coins were very thick (about 0.3 cm). Despite their small value, it took only a handful of such coins to fill one's pocket. They were also made of poor material and could be occasionally found with bite marks. The 1000 lei coin was considered too small and was also cheaply made, and the 5000 lei coin was not circular (it was a dodecagon). This made it awkward to handle and difficult to use in slot machines, where it was frequently the only coin accepted. The 500, 1000 and 5000 lei coins became worth 5, 10 and 50 bani with the revaluation.

In 1952, the Ministry of Finance introduced notes for 1, 3 and 5 lei, and the Banca Republicii Populare Romane introduced 10, 25 and 100 lei notes. In 1966, the Banca Nationala a Republicii Socialiste Romania took over the production of all paper money, issuing notes for 1, 3, 5, 10, 25, 50 and 100 lei.

In 1991, 500 and 1000 lei notes were introduced, followed by 200 and 5000 lei notes in 1992, 10,000 lei in 1994, 50,000 lei in 1996, 100,000 lei in 1998, 500,000 lei in 2000 and 1 million lei in 2003. There was also a 2000 lei note, introduced in 1999; it celebrated the total solar eclipse that occurred on August 11th, 1999. The final issues of the 2000, 10,000, 50,000, 100,000, 500,000 and 1 million lei were polymer notes.

Notes in circulation at the revaluation were:

* 10,000 lei (became 1 leu)
* 50,000 lei (became 5 lei)
* 100,000 lei (became 10 lei)
* 500,000 lei (became 50 lei)
* 1,000,000 lei (became 100 lei)

In 2005, polymer notes were introduced for 1, 5, 10, 50, 100 and 500 lei. 200 lei notes were added in 2006. The designs of the 1, 5, 10, 50 and 100 lei notes are based on those of the earlier 10,000, 50,000, 100,000, 500,000 and 1 million lei notes which they replaced. The 10 lei bill was redesigned in November 2008 (most of the graphic elements are identical, some of the safety elements were withdrawn, making its safety degree similar the the lower values of 1 leu and 5 lei bills).