From 1907 to 1908, he served in the military in Laon, and upon returning to Paris he had contact with the Cubists. The period of 1909–10 saw the emergence of Delaunay’s personal style; he painted his first Eiffel Tower in 1909 and received with great acclaim. Two years later, his 'City of Paris' caused a sensation at the Salon des Independents. Robert Delaunay's abstract works proved revolutionary in the development of French art. Apollinaire christened his style 'Orphism' in the way the art had similarities with the abstract in music. In 1910, Robert Delaunay married the painter Sonia Terk, who became his collaborator on many projects.
In 1911, at the invitation of Wassily Kandinsky, Delaunay joined The Blue Rider (Der Blaue Reiter), a Munich-based group of abstract artists. In 1912, he started to use pure colours and painted his first abstract pictures 'Disc' and 'Circular Forms'.
By 1914, Robert Delaunay was experimenting with wax. With the outbreak of the First World War he moved first to Portugal then to Spain and became friends with Sergei Diaghilev, Leonide Massine, Diego Rivera, and Igor Stravinsky. He designed decor for the Ballets Russes in 1918. By 1920 he had returned to Paris, where in 1922 an exhibition of his work was held at Galerie Paul Guillaume. He began his second Eiffel Tower series in that same year. In 1924 he undertook his Runner paintings and in 1925 executed frescoes for the Palais de l’Ambassade de France at the Exposition internationale des arts décoratifs in Paris.
He had always had grand ambitions for his art and these were fulfilled when he was commissioned to decorate the Palais des Chemins de Fer and Palais de l’Air at the Paris World’s Fair, in 1937. The following year with the help of his wife Sonia Delaunay and others he decorated the Tuileries Salon. Robert Delaunay died on October 25, 1941, in Montpellier, France.
Robert Delaunay's career as a painter was meteoric. He was a prominent spokesperson for a specific point of view at a time of much artistic fermentation in the years preceding World War I. Unlike such other highly regarded artists of that period as Picasso, Matisse, and Kandinsky, he did not sustain the innovations that propelled him into the limelight in his youth into his later work. As a result, his painting seems uneven after 1920 and his most significant work in the 1930s was murals and public commissions, an extension of his wife's early experiments. After his death in 1941, she continued to work prodigiously, designing books, tapestries, and fabrics, as well as interior decors and murals. Her work, as an extension of her husband's theories and early discoveries, helped to establish his reputation as a significant painter of the 20th century.
There are a number of good books written on the work of both Robert and Sonia Delaunay. Gustav Vrieson's Robert Delaunay: light and color (1969) is a standard, as is Robert Delaunay (1975), translated from the French with a text by Bernard Dorival.
"As an artist, as a manual craftsman, I wage my revolution on walls. I have now discovered new materials that can transform a wall, not only externally but in its very substance. Separate man from art? Never. I cannot separate man from art because I build houses for him! Even when fashion dictated easel art, I was already envisaging great murals."