The Napoléon is the colloquial term for a former French gold coin. The coins were minted (at various times) in denominations of 5, 10, 20, 40, 50, and 100francs. This article focuses on the 20 franc coins issued during the reign of Napoléon Bonaparte, which are 21 mm in diameter, weigh 6.45 grams (gross weight) and, at 90% pure, contain 0.1867 troy ounces or 5.805 grams of pure gold. The coin was issued during the reign of Napoleon I and features his portrait on the obverse. The denomination (known as the Franc Germinal) continued in use through the 19th century and later French gold coins in the same denomination were generally referred to as "Napoléons". Earlier French gold coins are referred to as Louis (the name of eighteen French kings) or écu (an old French word for shield). Gold Napoléons have historically proven more resilient than other gold coins to economic forces, such as after the Suez crisis when unlike other coins Napoléons did not weaken.
The coins were originally minted in two denominations, 20 and 40 francs for Napoléon Bonaparte. The 40-franc gold piece did not become popular. The 20 franc coins are 21 mm in diameter (about the size of a U.S. five cent piece or a Swiss 20 Rappen coin), weigh 6.45 grams (gross weight) and; at 90% pure, contain .1867 ounces or 5.805 grams of pure gold. The 40 franc coins are 26 mm in diameter, weigh 12.90 grams (gross weight) and; are 90% pure gold.
They were issued during the reign of Napoleon I and feature his portrait, sometimes bare headed and other times wearing a laurel wreath (the ancient Roman symbol of imperial or military glory) and, depending upon the political status of France, the words on the front: either Bonaparte – Premier Consul (First Consul) or Napoléon Empereur (emperor). On the back: the legends read either "RÉPUBLIQUE FRANÇAISE" (French Republic) or after 1809, "EMPIRE FRANÇAIS" (French Empire). There was even a 20 and 40 Lire Napoleon minted under the auspices of the Kingdom of Italy, a client state. "Bonaparte First Consul" pieces of similar size, weight and fineness were struck at the Turin Mint. The obverse recounts that Italy was liberated (legend: L'Italie Délivrée à Marengo Battle of Marengo) from Austria by Bonaparte at Marengo on 14 June 1800, whereat the French General Louis Desaix was killed. The reverse indicates the extent liberated lands, known as Gaul Subalpine as the "Eridania," or Northern Italy. The type was created pursuant to the decree of the Gaul Subalpine/Piedmontese government established after the Battle of Marengo (near Alessandria in Turin) and which existed from 16 June 1800, through 11 September 1802.