Ernst Beyeler was the main founder of Art Basel, world-scale annual art fair. He and his wife Hildy Beyeler were desperately involved in the arts throughout their lives. Their world-famous art collection is accessible to the public at the Fondation Beyeler, and today it comprises more than 400 classic modern and contemporary works, including Bonnard, Bacon, Kandinsky, Matisse, Monet, Picasso, Rothko, Giacometti, Mondrian, Dubuffet, Cézanne and many more. And one could literally learn the history of European modernism only from the Beyeler collection.
Beyeler originally intended to become an economist, but the outbreak of the Second World War prevented him from leaving Switzerland and instead he became apprenticed to Oskar Schloss, an antiquarian bookseller in Basel. When Schloss died in 1945, Beyeler took over the firm at age 24. He gradually moved into art dealing and had his first exhibition, of Japanese woodcuts, just two years later.
A key development in his career was the purchase in the early 1960s of 340 art works from the American banker, industrialist and art collector G. David Thompson. The collection included works by Georges Braque, Paul Cézanne, Paul Klee, Léger, Henri Matisse, Claude Monet, Pablo Picasso, and Mondrian. Beyeler bought 70 works by Alberto Giacometti from Thompson which were divided between the Kunsthaus Zürich, the Basel Kunstmuseum and the Kunstmuseum Winterthur. According to the Pittsburgh Quarterly, the "decision not to build a Thompson building clearly made Beyeler's fortune, and ironically, it is Beyeler who has a museum containing his collection and bearing his name in Basel, Switzerland."
Beyeler developed "close relationships with many of the twentieth century's great artists". He became friends with Picasso in the 1950s and when he visited Mougins in 1966, Picasso allowed him to choose 26 paintings to sell.
In 1973, the US$180,000 he paid for Willem de Kooning’s abstract landscape Police Gazette set a new record for the artist, as did the US$14.7 million he paid in 1989 for Fernand Léger's cubist painting Forms in Contrast. His art collection was eventually worth at least CHF 2 billion (£1.21 billion). In 2010, The Washington Post reported that his collection was "worth at least $1.85 billion".
In 1982, together with his wife, fellow art dealer Hilda "Hildy" Kunz, he founded the Beyeler Foundation to showcase his private collection.
Beyeler also helped to develop many of the world’s most important collections of modern art, both private and public. Thanks to Ernst Beyeler, the idea of the fair was to lure a new wave of collectors and enthusiasts into the postwar consumer society, rich in time, money and new means of global communication.