Klee and Kandinsky were towering figures of the modernist movement and were close, both as friends and artists. For a time they lived next door to one another and exchanged their artistic ideas on a daily basis. This unique book explores their 30-year relationship, from the time of the Blue Rider group around 1912, through the Bauhaus years in Weimar and Dessau until the late 1930s. With the culture of the Weimar Republic as a backdrop, this book traces the eventful history of an artistic friendship. Kandinsky's idealism is juxtaposed with Klee's irony and we learn that their relationship was characterised in equal measure by friendship and competitiveness, mutual influence and the need to establish distance. The focus is on the artistic dialogue they enacted through their art. They were joined by an aspiration to spiritualise art and explore its intrinsic laws. At the same time, Kandinsky's commitment to abstraction contrasted strongly with Klee's allegiance to natural models.