Appearing in the late nineteenth century, Art Nouveau spread rapidly in Europe through international exhibitions, travelling artists, letters and journals. The common impulse of many European artists to revolutionize previously used formal vocabulary makes it a decidedly European movement. Each country’s creative centres brought their own flavour to the style by appending local specificities (Jugendstil in Germany, Liberty Style in Italy, Style Sapin in Switzerland, Modernisme in Spain, Sezessionsstil in Austria …) in the field of architecture and decorative arts. Since 1999, the Réseau Art Nouveau Network has developed and maintained an active cooperation between many European participants involved in the study and preservation of European and International Art Nouveau heritage, as well as its promotion.