Several older French coins exist, including the sou (sometimes "sols"), the ecu, the livre, and older versions of the franc and centimes. The word "sou" eventually came to mean a coin of little or no value.
The ecu was a coin put into circulation during the reign of King Louis XV. Ecu are collector's items that have accumulated great worth, with the price varying based upon the condition of the coin.
Livre were coins put into circulation during Charlemagne's reign and were a marker worth 1 pound of silver each.
Older versions of the franc and centimes were minted from gold prior to World War I and date back to the French Revolution.