In this short period, which began with the 20th century and ended with the crash of the First World War, the French experienced one of the greatest cultural and technical upheavals in their country's history. It was like a happy interlude, idealized many years later and nostalgically referred to as the "Belle Epoque". Thanks to incredible film footage born with the century, now restored and colorized, we rediscover this almost miraculous artistic moment at the heart of a society that loved above all else to laugh and take pleasure in everything, despite the difficulties. An unprecedented journey back in time, to the sources of the contemporary France that was shaped in the years 1900 - 1914. A definitively republican France, but one that fancied itself an Empire. A Republic that would become secular by force of law, and which had to cope with unprecedented social tensions. An era that we don't know if it was truly beautiful, but which was undoubtedly fascinating.