The document provides background information on Der Blaue Reiter (The Blue Rider), an expressionist group formed in Germany in 1911 by Wassily Kandinsky, Franz Marc, and others. It discusses the philosophical influences on the group such as Theosophy and synesthesia, and how these influenced the non-representational use of color in their abstract paintings. It also summarizes Kandinsky's artistic development from representational works to his breakthrough to full abstraction around 1910-1911.