In 1911, in response to the rejection of one of Kandinsky's paintings from the annual NKVM exhibition, he and Franz Marc organized a rival exhibition and co-founded "Der Blaue Reiter" (The Blue Rider) - a loose association of nine Expressionist artists that included August Macke, Munter, and Jawlensky. Though their aims and approaches varied from artist to artist, in general the group believed in the promotion of modern art and the possibility for spiritual experience through the symbolic associations of sound and color - two issues very near and dear to Kandinsky's heart. Despite the similarities between the group's moniker and the title of Kandinsky's 1903 painting, the artists actually arrived at the name "Der Blaue Reiter" as a result of the combination of Marc's love of horses and Kandinsky's interest in the symbolism of the rider, coupled with both artists' penchant for the color blue. During their short tenure, the group published an anthology (The Blue Rider Almanac) and held three exhibitions. Additionally, Kandinsky published Concerning the Spiritual in Art (1911), his first theoretical treatise on abstraction that articulated his theory that the artist was a spiritual being that communicated through and was affected by line, color, and composition. He produced both abstract and figurative works at this time, but expanded his interest in non-objective painting.Composition VII (1913) was an early example of his synthesis of spiritual, emotional, and non-referential form through complex patterns and brilliant colors. The outbreak of World War I in 1914 led to the dissolution of Der Blaue Reiter, but, despite their short tenure, the group initiated and deeply inspired the highly influential German Expressionist style.
After Germany declared war on Russia, Kandinsky was forced to leave the country. He traveled to Switzerland and Sweden with Munter for almost two years, but returned to Moscow in early 1916, which effectively ended their relationship. In Moscow he courted and married Nina Andreevskaia, the young daughter of a Czarist colonel. While there, he not only became familiar with the art of Constructivists and Suprematists like Vladimir Tatlin and Kazimir Malevich, but also lived in the same building as Aleksander Rodchenko, and met other avant-garde luminaries like Naum Gabo, Lyubov Popova, and Varvara Stepanova. With the October Revolution in 1917, Kandinsky's plans to build a private school and studio were upset by the Communist redistribution of private wealth and instead, he worked with the new government to develop arts organizations and schools. Despite his participation in the development of the officially sanctioned new institutions, he felt increasingly removed from the avant-garde. His search for spirituality in art did not meld with the utilitarian aesthetic advocated by the young government and the artists it embraced.
In 1921, when architect Walter Gropius invited Kandinsky to Germany to teach at the Weimar Bauhaus, he accepted and moved to Berlin with his wife, gaining German citizenship in 1928. As a member of the innovative school, Kandinsky's artistic philosophy turned toward the significance of geometric elements - specifically circles, half-circles, straight lines, angles, squares, checkerboards, and triangles. In 1926, he published his second major theoretical work, Point and Line to Plane that outlined his ideas about a "science of painting." In both his work and theory he shifted from the romantic, intuitive expression of his pre-war canvases to an emphasis on constructively organized compositions.