The French Franc
The French Franc dates back to the 14th century. It was introduced in 1360 by King John II and basically served as the official French currency until the euro was introduced in 2002. There was another official currency in France between 1641 and 1795, but the name franc still continued in common usage by the people despite the change in currency.
Inflation Helple Create New Franc
As with most currencies, inflation eventually ate away at the value of the franc as the French government did what most governments in the world do: spent beyond its means. When a government spends too much it eventually devalues the currency if it can in order to pay its debts. In 1960, the "new" franc replaced the "old" franc, with 100 old francs worth one new franc.
Still Redeemable for Euro
Though the French franc will not buy you anything today in a shop in France or anywhere in Europe, many French francs are still redeemable for euros. If you somehow come across some francs and are wondering if they are worth anything, you can go to the website of Banque de France and see how much the franc notes are redeemable for, though many are no longer redeemable. As of 2010, none will be redeemable.
The Euro
Launched on January 1,1999, the euro is now the official currency of 17 countries in the European Union, including France. It was first a virtual currency that came into physical existence at the beginning of 2002. One major member of the European Union that did not adopt the euro was the United Kingdom, which continues to use the British pound as its official currency.