Paul Klee and Lily (actually Karoline) Stumpf married in 1906 and moved to Schwabingen, Munich’s bustlinbg artist quarter, shortly after. Kandinsky also lived in the same neighborhood, but he and Klee would not meet before 1911, when Kandinsky introduced Klee to the activities of the newly founded artist group “Der Blaue Reiter”. Over a period of 30 years, the two artists stayed friends and gave fundamental impetus to the avant-garde and the development of abstract art. After years of isolation, Klee now found a network of like-minded avant-garde artists, many of whom were also looking for a form of art that reflected an inner world beyond the outer appearances. Taking part in the second exhibition of the "Blaue Reiter" in 1912, he met other outstanding contemporary artists and writers such as Alexej von Jawlensky, Rainer Maria Rilke and Herwarth Walden. Since 1914, he put increasing focus on watercolors. The trip to Tunisia with August Macke and Louis René Moilliet marked the decisive step towards his own artistic style. Shortly before the trip, Klee cautiously embarked on the path of abstraction through color surfaces. He then consistently developed this principle on his famous journey to the northern African country. However, the strongest impact on Klee's art during these years came from Robert Delaunay. After he had first met the Frenchman at the first “Blaue Reiter” exhibition in December 1911, Klee visited the artist at his studio in the spring of 1912 during a short stay in Paris presenting a letter of recommendation from Kandinsky. Here he saw Delaunay's first steps in the groundbreaking Fenêtres series: he transformed the Parisian cityscape outside his studio window into a semi-abstract, prismatic lattice structure rich in subtly modulated colors. Later that same year, Klee delved further into Delaunay's theories and translated the French artist's essay "Sur la lumière" into German for the avant-garde magazine ‘Der Sturm’. The dissolution of the image object into colorful, sparkling prisms makes the color largely independent of nature and object. The independent value of the color and the nature of its interaction become the main protagonist of the composition. Klee clearly valued the watercolor "Das Fenster” (The Window) very much, as he chose it for his important early solo exhibition at the Moderne Galerie Thannhauser in Munich in March 1914, which then traveled on to Herwarth Walden’s renowned gallery ‘Der Sturm’ in Berlin. [SM]