The term écu or crown may refer to one of several French coins. The first écu was a gold coin (the écu d’or) minted during the reign of Louis IX of France, in 1266. Écu (from Latin scutum) means shield, and the coin was so called because its design included the coat of arms of France. The word is related to scudo and escudo. The value of the écu varied considerably over time, and silver coins (known as écu d’argent) were also introduced.
When Louis IX took the throne, France still used small silver deniers, which had circulated since the time of Charlemagne to the exclusion of larger silver or gold coins. Over the years, French kings had granted numerous nobles and bishops the right to strike coins and their “feudal” coinages competed with the royal coinage. Venice and Florence had already shown that there was demand for larger silver and gold coins and in 1266 Louis IX sought an advantage for the royal coinage by expanding it in these areas. His gold écu d’or showed a shield strewn with fleur-de-lis, which was the coat of arms of the kings of France at the time. These coins were valued as if gold was worth only 10 times as much as silver, an unrealistic ratio which Edward III of England had unsuccessfully tried to use. It failed again, Louis IX’s silver coins were a great success but his gold was not accepted at this rate and his successor discontinued gold coinage.