The expression Belle Epoque is a retrospective chrononym invented during the Second World War to mourn a lost world. It refers to the period of peace between the end of the Franco-Prussian War of 1870 and the start of the First World War in 1914. This period, considered beautiful afterward, was marked by socio-political and economic progress, an exceptional concentration in technological innovations and inventions as well as a strong intellectual and artistic creativity in painting, literature, or music. It has become the emblem of a certain French art of living whose splendor has radiated throughout the world in 1900 at the time of the Universal Exhibition in Paris that inaugurated the 20th century. The Villa du Temps Retrouvé in Cabourg was created as a promise of immersion in this lost world.