Paul Klee (18 December 1879 – 29 June 1940) was a Swiss-German artist. His highly individual style was influenced by movements in art that included Expressionism, Cubism, and Surrealism. Klee was a natural draftsman who experimented with and eventually deeply explored color theory, writing about it extensively; his lectures Writings on Form and Design Theory (Schriften zur Form und Gestaltungslehre), published in English as the Paul Klee Notebooks, are held to be as important for modern art as Leonardo da Vinci`s A Treatise on Painting for the Renaissance. He and his colleague, Russian painter Wassily Kandinsky, both taught at the Bauhaus school of art, design and architecture. His works reflect his dry humor and his sometimes childlike perspective, his personal moods and beliefs, and his musicality.

Paul Klee was born in Munchenbuchsee, Switzerland, as the second child of German music teacher Hans Wilhelm Klee (1849–1940) and Swiss singer Ida Marie Klee, nee Frick (1855–1921). In his early years, following his parents’ wishes, Klee focused on becoming a musician; but he decided on the visual arts during his teen years, partly out of rebellion and partly because of a belief that modern music lacked meaning for him. He stated, "I didn`t find the idea of going in for music creatively particularly attractive in view of the decline in the history of musical achievement." As a musician, he played and felt emotionally bound to traditional works of the eighteenth and nineteenth century, but as an artist he craved the freedom to explore radical ideas and styles. At sixteen, Klee’s landscape drawings already show considerable skill.

After receiving his Fine Arts degree, Klee went to Italy from October 1901 to May 1902 with friend Hermann Haller. They stayed in Rome, Florence, and Naples, and studied the master painters of past centuries. He exclaimed, "The Forum and the Vatican have spoken to me. Humanism wants to suffocate me." He responded to the colors of Italy, but sadly noted, "that a long struggle lies in store for me in this field of color." For Klee, color represented the optimism and nobility in art, and a hope for relief from the pessimistic nature he expressed in his black-and-white grotesques and satires. Returning to Bern, he lived with his parents for several years, and took occasional art classes. By 1905, he was developing some experimental techniques, including drawing with a needle on a blackened pane of glass, resulting in fifty-seven works including his Portrait of My Father (1906). In the years 1903-5 he also completed a cycle of eleven zinc-plate etchings called Inventions, his first exhibited works, in which he illustrated several grotesque characters. He commented, "though I`m fairly satisfied with my etchings I can`t go on like this. I’m not a specialist." Klee was still dividing his time with music, playing the violin in an orchestra and writing concert and theater reviews.

In January 1911 Alfred Kubin met Klee in Munich and encouraged him to illustrate Voltaire`s Candide. Around this time, Klee`s graphic work increased. His early inclination towards the absurd and the sarcastic was well received by Kubin, who befriended Klee and became one of his first significant collectors. Klee met, through Kubin, the art critic Wilhelm Hausenstein in 1911. Klee was a foundation member and manager of the Munich artists` union Sema that summer. In autumn he made an acquaintance with August Macke and Wassily Kandinsky, and in winter he joined the editorial team of the almanac Der Blaue Reiter, founded by Franz Marc and Kandinsky. On meeting Kandinsky, Klee recorded, "I came to feel a deep trust in him. He is somebody, and has an exceptionally beautiful and lucid mind." Other members included Macke, Gabriele Munter and Marianne von Werefkin. Klee became in a few months one of the most important and independent members of the Blaue Reiter, but he was not yet fully integrated.

Klee`s artistic breakthrough came in 1914 when he briefly visited Tunisia with August Macke and Louis Moilliet and was impressed by the quality of the light there. He wrote, "Color has taken possession of me; no longer do I have to chase after it, I know that it has hold of me forever... Color and I are one. I am a painter." With that realization, faithfulness to nature faded in importance. Instead, Klee began to delve into the "cool romanticism of abstraction". In gaining a second artistic vocabulary, Klee added color to his abilities in draftsmanship, and in many works combined them successfully, as he did in one series he called "operatic paintings". One of the most literal examples of this new synthesis is The Bavarian Don Giovanni (1919).

After returning home, Klee painted his first pure abstract, In the Style of Kairouan (1914), composed of colored rectangles and a few circles. The colored rectangle became his basic building block, what some scholars associate with a musical note, which Klee combined with other colored blocks to create a color harmony analogous to a musical composition. His selection of a particular color palette emulates a musical key. Sometimes he uses complementary pairs of colors, and other times "dissonant" colors, again reflecting his connection with musicality.

A few weeks later, World War I began. At first, Klee was somewhat detached from it, as he wrote ironically, "I have long had this war in me. That is why, inwardly, it is none of my concern." Klee was conscripted as a Landsturmsoldat (soldier of the reserve forces in Prussia or Imperial Germany) on 5 March 1916. The deaths of his friends August Macke and Franz Marc in battle began to affect him. Venting his distress, he created several pen and ink lithographs on war themes including Death for the Idea (1915). After finishing the military training course, which began on 11 March 1916, he was committed as a soldier behind the front. Klee moved on 20 August to the aircraft maintenance company in Oberschleissheim, executing skilled manual work, such as restoring aircraft camouflage, and accompanying aircraft transports. On 17 January 1917, he was transferred to the Royal Bavarian flying school in Gersthofen (which 54 years later became the USASA Field Station Augsburg) to work as a clerk for the treasurer until the end of the war. This allowed him to stay in a small room outside of the barrack block and continue painting.

In 1919, Klee applied for a teaching post at the Academy of Art in Stuttgart. This attempt failed but he had a major success in securing a three-year contract (with a minimum annual income) with dealer Hans Goltz, whose influential gallery gave Klee major exposure, and some commercial success. A retrospective of over 300 works in 1920 was also notable.

Klee taught at the Bauhaus from January 1921 to April 1931. He was a "Form" master in the bookbinding, stained glass, and mural painting workshops and was provided with two studios. In 1922, Kandinsky joined the staff and resumed his friendship with Klee. Later that year the first Bauhaus exhibition and festival was held, for which Klee created several of the advertising materials. Klee welcomed that there were many conflicting theories and opinions within the Bauhaus: "I also approve of these forces competing one with the other if the result is achievement."

Klee was also a member of Die Blaue Vier (The Blue Four), with Kandinsky, Lyonel Feininger, and Alexej von Jawlensky; formed in 1923, they lectured and exhibited together in the USA in 1925. That same year, Klee had his first exhibits in Paris, and he became a hit with the French Surrealists. Klee visited Egypt in 1928, which impressed him less than Tunisia. In 1929, the first major monograph on Klee`s work was published, written by Will Grohmann.

Klee also taught at the Dusseldorf Academy from 1931 to 1933, and was singled out by a Nazi newspaper, "Then that great fellow Klee comes onto the scene, already famed as a Bauhaus teacher in Dessau. He tells everyone he`s a thoroughbred Arab, but he`s a typical Galician Jew." His home was searched by the Gestapo and he was fired from his job. His self-portrait Struck from the List (1933) commemorates the sad occasion. In 1933-4, Klee had shows in London and Paris, and finally met Pablo Picasso, whom he greatly admired. The Klee family emigrated to Switzerland in late 1933.

Klee was at the peak of his creative output. His Ad Parnassum (1932) is considered his masterpiece and the best example of his pointillist style; it is also one of his largest, most finely worked paintings. He produced nearly 500 works in 1933 during his last year in Germany. However, in 1933, Klee began experiencing the symptoms of what was diagnosed as scleroderma after his death. The progression of his fatal disease, which made swallowing very difficult, can be followed through the art he created in his last years. His output in 1936 was only 25 pictures. In the later 1930s, his health recovered somewhat and he was encouraged by a visit from Kandinsky and Picasso. Klee`s simpler and larger designs enabled him to keep up his output in his final years, and in 1939 he created over 1,200 works, a career high for one year. He used heavier lines and mainly geometric forms with fewer but larger blocks of color. His varied color palettes, some with bright colors and others sober, perhaps reflected his alternating moods of optimism and pessimism. Back in Germany in 1937, seventeen of Klee`s pictures were included in an exhibition of "Degenerate art" and 102 of his works in public collections were seized by the Nazis.

Klee suffered from a wasting disease, scleroderma, toward the end of his life, enduring pain that seems to be reflected in his last works of art. One of his last paintings, Death and Fire, features a skull in the center with the German word for death, "Tod", appearing in the face. He died in Muralto, Locarno, Switzerland, on 29 June 1940 without having obtained Swiss citizenship, despite his birth in that country. His art work was considered too revolutionary, even degenerate, by the Swiss authorities, but eventually they accepted his request six days after his death. His legacy comprises about 9,000 works of art. The words on his tombstone, Klee`s credo, placed there by his son Felix, say, "I cannot be grasped in the here and now, For my dwelling place is as much among the dead, As the yet unborn, Slightly closer to the heart of creation than usual, But still not close enough." He was buried at Schosshaldenfriedhof, Bern, Switzerland.