His theories are mostly concerned with color and light and influenced many, including Stanton Macdonald-Wright, Morgan Russell, Patrick Henry Bruce, Der Blaue Reiter, August Macke, Franz Marc, Paul Klee, and Lyonel Feininger.

Art critic Guillaume Apollinaire was strongly influenced by Delaunay's theories of color and often quoted from them to explain Orphism, which he had named.

night scene, for example, has vigorous activity, with the use of lively brushstrokes in bright colors against a dark background, not defining solid objects but the areas that surround them.

In the Eiffel Tower the interpenetration of tangible objects and space is accompanied by the intense movement of geometric planes that are more dynamic than the static equilibrium of Cubist forms.

While he was a child, Delaunay's parents divorced, and he was raised by his mother's sister Marie and her husband Charles Damour, in La Ronchère near Bourges.

When he failed his final exam and said he wanted to become a painter, his uncle in 1902 sent him to Ronsin's atelier to study Decorative Arts in the Belleville district of Paris.

[4] Delaunay formed a close friendship at this time with Jean Metzinger, with whom he shared an exhibition at a gallery run by Berthe Weill early in 1907.

The two of them were singled out by the art critic Louis Vauxcelles in 1907 as Divisionists who used large, mosaic-like 'cubes' to construct small but highly symbolic compositions.

"[6] Herbert describes the vibrating image of the sun in Metzinger's painting, and so too of Delaunay's Paysage au disque (1906–07), as "an homage to the decomposition of spectral light that lay at the heart of Neo-Impressionist color theory..."[7] Metzinger, followed closely by Delaunay—the two often painting together in 1906 and 1907—would develop a new sub-style of Neo-Impressionism that had great significance shortly thereafter within the context of their Cubist works.

[6] In 1908, after a term in the military working as a regimental librarian, he met Sonia Terk; at the time she was married to a German art dealer whom she would soon divorce.

The same year, at the invitation of Wassily Kandinsky, Delaunay joined The Blue Rider (Der Blaue Reiter), a Munich-based group of artists.

The exhibition, organized by the French mathematician and actuary Maurice Princet, showed forty-six works from his early 1906-07 Divisionist period to his Proto-Cubist and Cubist Eiffel Tower paintings from 1909 to 1912.

In the 23 March 1912 issue of the satirical magazine L'Assiette au Beurre, the first published suggestion that Delaunay had broken with this group of Cubists appeared, in James Burkley's review of the Salon des Indépendants.

[4] The Russian Revolution brought an end to the financial support Sonia received from her family in Russia, and a different source of income was needed.

[4] Robert Delaunay's works can be found in museums and loaned from private collections around the world: The Musée National d'Art Moderne in Paris, the Musée d'Art Moderne de Paris, the Neue Nationalgalerie in Berlin, the Bilbao Fine Arts Museum (Spain), Kunstmuseum Basel (Switzerland), the National Galleries of Scotland, the New Art Gallery (Walsall, England), Palazzo Cavour (Turin, Italy), the Peggy Guggenheim Collection (Venice), National Museum of Serbia, Van Abbemuseum (Eindhoven, The Netherlands), Palais des Beaux-Arts de Lille (France).