Bordeaux wine regions all the producers within a given area: rather, only the producers (universally known as "châteaux", although not usually possessing the architectural grandeur that might imply) perceived as being of an unusually high standard are included in the classification. The châteaux included in the classification are referred to as "classed" or "classé", and those not included are referred to as "unclassed". Some classifications sub-divide the classed châteaux, according to the perceived quality. On the Left Bank, the Bordeaux Wine Official Classification of 1855 is the starting point for classification. Although this purports to be a classification of all Bordeaux wine, it
History of French wine known as chaptalization. Chaptal's treatise was a turning point in the history of wine technology as it synthesized the knowledge current to the beginning of the 19th century. By the mid 19th century, the wine industry of France enjoyed a golden period of prosperity. A new class of consumers, the bourgeoisie, emerged as a strong market for wine and other culinary products. The Gironde region of Bordeaux, in particular, enjoyed a swell of interest from both the Parisian market as well as its steady trade with England. For the 1855 Paris Exposition, Emperor Napoleon III commissioned the Bordeaux merchants to