The term écu may refer to one of several French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 coin

Coin

A coin is a piece of hard material that is standardized in weight, is produced in large quantities in order to facilitate trade, and primarily can be used as a legal tender token for commerce in the designated country, region, or territory....

s. The first écu was a gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 coin (the écu d'or) minted during the reign of Louis IX of France

Louis IX of France

Louis IX , commonly Saint Louis, was King of France from 1226 until his death. He was also styled Louis II, Count of Artois from 1226 to 1237. Born at Poissy, near Paris, he was an eighth-generation descendant of Hugh Capet, and thus a member of the House of Capet, and the son of Louis VIII and...

, in 1266. Ecu (from Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 scutum) means shield, and the coin was so called because its design included a shield bearing a coat of arms

Coat of arms

A coat of arms is a unique heraldic design on a shield or escutcheon or on a surcoat or tabard used to cover and protect armour and to identify the wearer. Thus the term is often stated as "coat-armour", because it was anciently displayed on the front of a coat of cloth...

. The word is related to scudo

Scudo

The scudo has been used as a unit of currency in several different states:* Bolivian scudo* Italian scudo* Lombardy-Venetia scudo* Maltese scudo* Milanese scudo* Papal States scudo* Piedmont scudo* Sardinian scudoOther meanings:...

 and escudo

Escudo

The escudo is a unit of currency. Historically it was used in Portugal and in its colonies, and is still used in Cape Verde to this day. Escudo is Portuguese for "shield"...

. The value of the écu varied considerably over time, and silver

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 coins (known as écu d'argent) were also introduced.

In the 17th and 18th centuries, the name écu was applied exclusively to a large silver coin (introduced by Louis XIII

Louis XIII of France

Louis XIII was a Bourbon monarch who ruled as King of France and of Navarre from 1610 to 1643.Louis was only eight years old when he succeeded his father. His mother, Marie de Medici, acted as regent during Louis' minority...

 in 1640) initially worth three livres tournois

Livre tournois

The livre tournois |pound]]) was:#one of numerous currencies used in France in the Middle Ages; and#a unit of account used in France in the Middle Ages and the early modern period.-Circulating currency:...

. From 1690 to 1725 rates were unstable and new écus were issued, and existing écus revalued. After 1726 the final écu remained stable at six livres tournois

Livre tournois

The livre tournois |pound]]) was:#one of numerous currencies used in France in the Middle Ages; and#a unit of account used in France in the Middle Ages and the early modern period.-Circulating currency:...

. The silver écu (sometimes also called the louis d'argent) was further broken down into a 1/4 value coin (the quart d'écu) and a 1/2 value coin (the demi-écu). For more on the 17-18th century currency system, see Louis (coin), livre tournois

Livre tournois

The livre tournois |pound]]) was:#one of numerous currencies used in France in the Middle Ages; and#a unit of account used in France in the Middle Ages and the early modern period.-Circulating currency:...

 and Italian scudo

Italian scudo

The scudo was the name for a number of coins used in Italy until the 19th century. The name, like that of the French écu and the Spanish and Portuguese escudo, was derived from the Latin scutum . From the 16th century, the name was used in Italy for large silver coins...

.

The écu disappeared during the French Revolution

French Revolution

The French Revolution , sometimes distinguished as the 'Great French Revolution' , was a period of radical social and political upheaval in France and Europe. The absolute monarchy that had ruled France for centuries collapsed in three years...

, but the 5 francs silver coins minted throughout the 19th century were but the continuation of the old écus, and were often still called écu by French people.

The écu, as it existed immediately before the French Revolution

French Revolution

The French Revolution , sometimes distinguished as the 'Great French Revolution' , was a period of radical social and political upheaval in France and Europe. The absolute monarchy that had ruled France for centuries collapsed in three years...

, is approximately equivalent (in terms of purchasing power) to 20 euro

Euro

The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...

 or 25 dollars in 2006.
The fact that the coin's name was the same as ECU, the abbreviation of the European Currency Unit

European Currency Unit

The European Currency Unit was a basket of the currencies of the European Community member states, used as the unit of account of the European Community before being replaced by the euro on 1 January 1999, at parity. The ECU itself replaced the European Unit of Account, also at parity, on 13...

, may have assisted the ECU's adoption by France despite its being an acronym of English words.