Daniel-Henry Kahnweiler

Kahnweiler was born in Mannheim in 1884 and sent to Paris to train for finance. In February 1907, aged twenty-three, he used a small inheritance to open a gallery four metres square on the rue Vignon, and chose to sell the least sellable art in the city. Within two years he was buying the whole output of Picasso, Georges Braque, Juan Gris and Fernand Léger under exclusive contract — the arrangement that let four painters take the figure apart without waiting for a market to approve of it. He introduced Picasso to Braque, and between 1908 and 1915 he bought most of what the pair made.

The First World War nearly ended him. As a German citizen in France he was declared an enemy alien, his stock was seized as a war trophy on 12 December 1914, and after the war the French state auctioned roughly three thousand works at the Hôtel Drouot in four sales between 1921 and 1923 — Cubism's first decade sold off cheap by the government, its own dealer barred from the room. He had spent the war in neutral Switzerland writing Der Weg zum Kubismus (The Rise of Cubism, 1920), the movement's first book-length account. He came back to Paris in 1920 and opened again under a partner's name, the Galerie Simon, publishing more than forty illustrated books pairing living painters with living writers. In 1941, to keep the Nazi occupation from expropriating a Jewish firm, the gallery was renamed for his sister-in-law Louise Leiris. He died in Paris in 1979, having represented Picasso, on and off, for most of sixty years.