The decimal "franc" was established as the national currency by the French Revolutionary Convention in 1795 as a decimal unit (1 franc = 10 decimes = 100 centimes) of 4.5 g of fine silver. This was slightly less than the livre of 4.505 g but the franc was set in 1796 at 1.0125 livres (1 livre, 3 deniers), reflecting in part the past minting of sub-standard coins.
In 1803, the "germinal franc" (named after the month Germinal in the revolutionary calendar) was established, creating a gold franc containing 290.32 mg of fine gold. From this point, gold and silver-based units circulated interchangeably on the basis of a 1:15.5 ratio between the values of the two metals (bimetallism). This system continued until 1864, when all silver coins except the 5 franc piece were debased from 90% to 83.5% silver without the weights changing.
France was a founding member of the Latin Monetary Union (LMU) in 1865. The common currency was based on the franc germinal, with the name franc already being used in Switzerland and Belgium, whilst other countries used their own names for the currency. In 1873, the LMU went over to a purely gold standard of 1 franc = 0.290322581 g gold.
The outbreak of World War I caused France to leave the gold standard of the LMU. The war severely undermined the franc's strength, as war expenditure, inflation and postwar reconstruction, financed partly through the printing of ever more money, reduced the franc's purchasing power by 70% from 1915 to 1920 and a further 43% from 1922 to 1926. After a brief return to the gold standard (1928 to 1936) the currency was allowed to resume its slide, until it was worth in 1959 less than a fortieth of its 1934 value.
The third coins were issued in denominations of 1 and 5 centimes, 1 and 2 decimes (in copper), quarter, half, 1, 2, and 5 francs (in silver), and 20 and 40 francs (in gold). Copper coins were not issued between 1801 and 1848, leaving the quarter-franc as the smallest coin being minted. During this period, copper coins from the previous currency system circulated, with a one-sou coin being valued at 5 centimes.