It was in England that crystal was first produced, thanks to a ban. The one decreed in 1615 by King James I to reserve the use of wood for the English Navy. The glassmakers were then forced to modify the glass recipe to find a flux suitable for coal, their new fuel. After several unsuccessful attempts, George Ravenscroft added lead oxide and obtained a brilliant glass with a unique sound, the crystal. Within a few years, the glassworks across the Channel surpassed those in Venice and Bohemia. In France, the first to crack the English secret, in 1781, was the Saint-Louis glassworks.