The birth of this collection was based on an idea by Pierre Marchand, then directed by Élisabeth de Farcy. There are 588 volumes plus more than 150 books of spin-offs in this collection, each book focuses on a particular topic, such as history and archaeology, culture and society, art and aesthetics, science and technology, a biography of a famous person, or memories of places, etc. The whole collection covers almost everything of human knowledge. The A6 paper size (125 × 178 mm) is used for these pocket books and printed on thick and glossy coated paper, with a lot of full colour illustrations extracted from heritage resources to decorate the informational texts. Each book has a “Documents” section, more detailed documentary information and historical records are provided here, as well as the sources of all illustrations for those who want to learn further.