The origin of the French horn is obscure, but the likelihood is that it originated, true to its name, in France. The unmechanized horn (the French trompe or cor de chasse), the key depending on tube length, came into its own early in the 18th century. During the 1820s, by the invention of the valve, the horn became fully chromatic, even though prejudice against the valve horn, especially in France, remained for many years.