The museum of Celtic and Gallo-Roman Antiquities, inaugurated by Napoleon the Third on the 12th of May 1867, cannot be understood without its context, the construction of national mythologies in the 19th century, as Denmark’s pioneering 1807 Museum of National Antiquities or Mainz’ 1852 Roman-Germanic Central Museum testify. The MAN, for Musée des Antiquités Nationales, as it is known, is also the result of the Emperor’s personal investment in the promotion of archaeology, an investment that mixes political “cesarism” and personal passion, but also aims at establishing archaeology as a science. Jacques Boucher de Perthes’ discoveries in the Somme valley give birth to prehistory and to the emergence of an “antediluvian France”, a context that also dominates the first years of the museum in Saint-Germain. With the Museum as with the Commission de la topographie des Gaules, the Empire wants to be able to answer to the issue of the origins of France and contribute to the continuity of the story of the nation. The visitor’s instruction and the citizen’s education in parallel to the striving for universality are thus the first aspirations of this major museum institution.