Auction introduction: Sotheby’s is privileged and pleased to present the Collection of Robert and Helga Ehret. Beginning in the 1970’s, the couple’s collection of works ranging from Edgar Degas to Ernst Wilhem Nay, through Lyonel Feininger and Emil Nolde, attests to their unbridled enthusiasm for the experiences of modernity in general and the outbursts of the German avant-garde at the turn of the century. True rarity in France, an important work by Franz Marc, shows the spirit of refinement and audacity that presided, work after work, over the formation of this collection. Painted in 1911, the same year the Blaue Reiter movement was founded by Wassily Kandinsky, August Macke, Alexej von Jawlensky and Gabriele Münter, Stier (Bull) is one of the works of this romantic and dazzling bestiary that gave its name to the movement.