[1] The foundation was managed for decades by Bührle's son Dieter, who was sentenced to a conditional prison term of 8 months in 1970 for supplying weapons to the racist apartheid regime in South Africa.

[2] Although the collection includes a number of Old Masters and Modern art including works by Pierre Bonnard, Georges Braque, Henri Matisse, and Pablo Picasso,[3] it comprises mainly French Impressionism and Post-Impressionism paintings by Paul Cézanne, Edgar Degas, Paul Gauguin, Édouard Manet, Claude Monet, Camille Pissarro, Pierre-Auguste Renoir, Georges Seurat, Alfred Sisley, Henri de Toulouse-Lautrec, Vincent van Gogh and others.

Bührle bought his gothic sculptures in the shop of Benno Griebert, a member of Hitler's party NSDAP and ardent Nazi supporter.

[4] Bührle was only able to acquire his art collection with profits from the sale of weapons worth 623 million francs to Adolf Hitler's army.

[5][6] The four paintings were: Cézanne's Boy in the Red Vest (1894/1895), Degas's Count Lepic and His Daughters (1871), Monet's Poppies near Vétheuil (1879) and Van Gogh's Blossoming Chestnut Branches (1890).