The franc (/fræŋk/; French: [fʁɑ̃]; sign: F or Fr), also commonly distinguished as the French franc (FF), was a currency of France. Between 1450 and 1999, it was the name of coins worth 1 livre tournois and it remained in common parlance as a term for this amount of money. It was reintroduced (in decimal form) in 1795. It was revalued in 1960, with each new franc (NF) being worth 100 old francs. The NF designation was continued for a few years before the currency returned to being simply the franc; the French continued to reference and value items in terms of the old franc (equivalent to the new centime) until the introduction of the euro in 1999 (for accounting purposes) and 2002 (for coins and banknotes). The French franc was a commonly held international reserve currency of reference in the 19th and 20th centuries.

The first franc was a gold coin introduced in 1360 to pay the Ransom of King John II of France. This coin secured the king's freedom and showed him on a richly decorated horse earning it the name franc à cheval (meaning "free on horse" in French). The obverse legend, like other French coins, gives the king’s title as Francorum Rex ("King of the Franks" in Latin) and provides another reason to call the coin a franc. Its value was set as one livre tournois (a money of account). John’s son, Charles V, continued this type. It was copied exactly at Brabant and Cambrai and, with the arms on the horse cloth changed, at Flanders. Conquests led by Joan of Arc allowed Charles VII to return to sound coinage and he revived the franc à cheval. John II, however, was not able to strike enough francs to pay his ransom and he voluntarily returned to English captivity.

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