The term 'Bygone French Coin' refers to a variety of coins that were used in France before the introduction of the Euro. The ECU (3 letters) was a unit of account used by the European Union from 1979 to 1998. The SOU (3 letters) was a French coin that was minted from 1577 to 1795. The OBOLE (5 letters) was a small silver coin used in France from the 16th century until the 19th century. The EURO (4 letters) is the current currency of the European Union, which replaced the ECU in 1999. The FRANC (5 letters) was the currency of France from 1795 to 2002, when it was replaced by the Euro.