Modern art in Croatia began with the secessionist ideas spreading from Vienna and Munich, and post-impressionism from Paris. The Munich Circle used values to create volume in their paintings, in a style much simplified from more detailed earlier, academic style. The Medulic Society of sculptors and painters from Split brought themes of national history and legends to their art, and some of the artwork following the First World War contained a strong political message against the ruling Austro-Hungarian state. The Zagreb Spring Salon provided an annual showcase of the local art scene, and a big change was noticeable in 1919 with a move to flatter forms, and signs of cubism and expressionism were evident. The avant-garde Zenit Group of the 1920s pushed for integrating the new art forms with the native cultural identity. At the same time, the Earth Group sought to reflect reality and social issues in their art, a movement that also saw the development of naive art. The 1930s saw a return to more simple, classical styles.