Bela Petheo was born in Budapest, and received an M.A. in art history in 1956 from the University of Budapest. He escaped Hungary shortly after the Communist takeover in 1957 and immigrated to Vienna. The recipient of a Rockefeller scholarship, Petheo studied at Karl Lueger University and the Academy of Fine Arts, and for a brief time had contact with Oskar Kokoschka's "School of Seeing." In 1959 he immigrated to the United States and enrolled at the University of Chicago in 1961. He received his MFA in painting and printmaking in 1963.

The artist Harold Haydon had suggested Petheo to William McNeill as the illustrator of his book, after McNeill had interviewed and rejected five other illustrators. During their initial meeting, McNeill handed Petho a list of the concepts he wished to have illustrated and instructed Petheo to compose a few sketches. The drawing entitled "The Industrial Revolution" earned Petheo the $2000 commission to illustrate The Rise of the West.