Franc, the monetary unit in France, Belgium, and Switzerland. The first coins having this name were struck under John the Good of France in 1360; they bore the impression of the king on horseback, and the device Francorum rex, and were called francs d dieted; they were of fine gold, and were worth 1 pound {livre), or 20 sols, and weighed 2 1/2 pennyweights. Under Charles V. the impression was of the king on foot, and they were styled francs d pied, but retained the same value. Under Charles VII. their weight was reduced to about two pennyweights. The first silver francs were coined by Henry III. in 1575, and presented on one side the head of the king, and on the other a decorated cross, and weighed535833 pennyweight, and had a current value of 20 sous. Henry III. also coined half-francs and quarter-francs. In 1602 the value of the franc was increased to 21 sous. Having suffered many alterations, chiefly from clipping, Louis XIII. prohibited its circulation for more than its actual value, and substituted the silver louis of 60, 30, 15, and 5 sous value. The franc then ceased to be real money, but remained a unit of valuation.

On the adoption of the decimal system, in 1795, it was chosen as the monetary unit, being divided into tenths, called declines, and into hundredths, called centimes; it had a legal weight of 3.215 pennyweights, 9/10 fine; and coins were struck of 2 and 5 francs value in silver, and of 20, 50, and 100 francs in gold. In Switzerland the franc was adopted as the unit, along with the whole French monetary system, May 7, 1850. In 1864 the pieces of 50 and 20 centimes value were replaced by pieces of equal nominal but less intrinsic worth. After the monetary convention between France, Belgium, Italy, and Switzerland, in 1866, the standard franc of the law of 1795 ceased to exist except in the five-franc pieces; the pieces of 50 and 20 centimes value being reduced to .835 of pure silver instead of900, and the law requiring their withdrawal from circulation when they have lost .05 in weight.