The franc, also commonly distinguished as the French franc (FF), was a currency of France. Between 1360 and 1641, 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 in the 19th and 20th centuries.
Before World War I, when France was firmly on the gold standard, a franc was worth about 19 cents, or 5.18 to the dollar. It declined drastically in the '20s, to 25 to the dollar, i.e., 4 cents. That's one reason Americans of little means found France such a great place to live. After Britain, and then the U.S. abandoned the gold standard, the franc actually rose to about 15 to the dollar by 1935. Of course there was terrible inflation after World War II — in the end, the old franc literally wasn't worth a sou.
These are banknotes issued during the Vichy France regime, officially the French State (État français), during World War II.
In 1941, the Chief of the French State, Philippe Pétain, ordered that the previous Banque de France (BDF) banknote series should be replaced.
Instead of allegories and mythological figures, the new banknotes portrayed professions, family values and historical figures:
5 cinq french francs: Pyrenean shepherd (berger), woman and flowers on back. This banknote is the smallest French note ever issued.
10 dix french francs: Miners, mother and young child on back
20 vingt french francs: Breton Fisherman, 2 women and child on back
100 cent french francs: René Descartes, philosopher, angel on back
500 cinq cents french francs: Jean-Baptiste Colbert, politician, sailing ships and docks on back
1000 mille french francs: Demeter with child, bronze statue of Mercury against panorama of Rouen on back