Cooper Hewitt says...

Julio de Diego (American, b. Spain, 1900-1979) left his parents’ home in Madrid at age 15 and held his first exhibition at a casino. He became an apprentice in a studio that produced opera scenery, once appearing as an extra in a Ballets Russes production, and subsequently served for several years in the Spanish army. After the Rif War of 1920 in northern Africa, Diego traveled to Paris and then immigrated to the United States in 1924. By 1926, he had settled in Chicago, where he worked as a commercial artist. He decorated two chapels in St. Gregory’s Church and created fashion illustrations and magazine covers.
He also focused on painting and began exhibiting at the Art Institute of Chicago in 1929. In 1935, he held a solo exhibition there.
Diego was married briefly while in Chicago and had one daughter, Kiriki. After the marriage ended, he moved to Mexico, where he collected native artifacts and made a living designing ballet scenery and costumes. He also took up jewelry making and his work was included in an exhibition of handmade jewelry at the Museum of Modern Art in New York.
In 1948, he married Gypsy Rose Lee, with whom he joined Royal American Shows, a traveling carnival. The couple divorced, and Diego moved to California.
He painted in the Renaissance method of velatura, building up as many as 40 thin layers of opaque oil paint on one surface. His work was increasingly political, reflecting themes of World War II, atomic energy, and natural disasters. He supported the American Artists’ Congress, a radical group that opposed censorship and fascism. During this time, he also taught at the University of Denver and Artist Equity Workshop.
Late in his life, Diego settled in the artists’ colony in Sarasota, Florida. He died there at age 79.