This TV program tries to show how the illustration from the 17th to 20th century of the famous novel written by Cervantès has in the same time improved and impoverished our knowledges of this novel. Improved, because the illustration help us to discover that the physical aspect of the caracters influences the comical features and the symbolism of this masterpiece. Impoverished, because it neglected, especially since the 19th century, the representation of the age and the context, thus favoring abusive adaptations and condensations.