Originally the "Cordon Bleu" ("blue ribbon") comes from L'Ordre des Chevaliers du Saint Esprit, an elite group of French knights created in 1578. Each member was awarded the Cross of the Holy Spirit, which hung from a blue ribbon.
At the end of the 19th century a French culinary magazine, La Cuisinière Cordon Bleu, was published. The magazine began offering lessons by some of the best chefs in France. This grew to become a cooking school that opened in Paris in 1895 and which became recognized as one of the most elite cooking schools in the world.
By extension it refers now to a cook of the highest class.
