Short answers, pulled from the story.
The French franc was a currency of France. Between 1360 and 1641 it was the name of coins worth 1 livre tournois, it was reintroduced in decimal form in 1795, and it remained in use until the euro replaced it for coins and banknotes in 2002.
The gold franc introduced in 1360 showed King John II of France on a richly decorated horse, earning the name franc a cheval, meaning free on horseback. The coin's legend also named the king as Francorum Rex, King of the Franks, giving another reason to call it a franc.
France introduced the new franc, the nouveau franc, in January 1960, with 100 old francs making one new franc. The abbreviation NF was used on the 1958 design banknotes until 1963.
The French franc was converted to the euro at a fixed rate of 6.55957 francs to 1 euro. This parity was set from the 1st of January 1999, and euro coins and notes replaced the franc entirely between January and March 2002.
The National Convention of Revolutionary France established the decimal franc as the national currency in 1795, with one franc equal to 10 decimes or 100 centimes and set at 4.5 grams of fine silver. The franc became the official currency of France in 1799.
During the Nazi occupation of France from 1940 to 1944, the franc was a satellite currency of the German Reichsmark at an exchange rate of 20 francs for 1 Reichsmark. Vichy coins replaced the motto Liberte, egalite, fraternite with Travail, famille, patrie and added the regime's emblem.