Which art dealer signed exclusive contracts with Picasso and Braque?

Daniel-Henry Kahnweiler signed exclusive contracts with Pablo Picasso and Georges Braque.

Kahnweiler was a German-born art dealer who opened his Paris gallery in 1907. Rather than catering to a broad public, he supported a small circle of innovative artists and promoted their work to serious collectors. His gallery became one of the most important early commercial centers for Cubism.

Before the First World War, Kahnweiler guaranteed artists such as Picasso, Braque, Juan Gris and, to a lesser extent, Fernand Léger an annual income in exchange for the exclusive right to buy their works. This arrangement gave them financial stability and room to experiment while limiting immediate public exposure.

Kahnweiler was not the inventor of Cubism; Picasso and Braque developed the style through their artistic partnership in Paris. His importance was that of a committed dealer, patron and advocate who helped preserve, sell and explain their work. Paul Durand-Ruel, Ambroise Vollard and Berthe Weill were also influential dealers, but they are not the canonical answer to this contract question.