Born Daniel Henry Kahnweiler in Mannheim, Germany, he was the son of a prominent German stock broker. In 1902 his family sent him to work at the Stock Exchange in Paris, France, where he used his spare time to visit the city?s various museums and art galleries. His passion for the arts led to his giving up his financial career. Using his business acumen, he became an art dealer and in 1907 opened his own gallery at 28 rue Vignon in Paris.
Along with such men as Alfred Flechtheim, Paul Cassirer, and Daniel Wildenstein, Kahnweiler was one of the most extraordinary and unique art connoisseurs of the 20th century. Rather than exhibiting the popular works of the past and present greats, Kahnweiler championed burgeoning artists such as André Derain, Alberto Giacometti, and others, who had come from all over the globe to live and work in Montparnasse at the time.
Kahnweiler gave the first exhibition of the work of Georges Braque, and soon he expanded his presentations by bringing together artists, writers and poets to produce their works as a joint project in more than 40 books. He published Max Jacob, Guillaume Apollinaire, André Masson and others. Henry Kahnweiler was the first to recognize the radical greatness of Pablo Picasso, and promoted the new Cubist movement of Braque, Juan Gris, Fernand Leger and Picasso.
In July 1914 Kahnweiler and his family were holidaying in Bavaria. On seeing the German reservists being mobilised he realised that war was now inevitable. He decamped to Italy and then chose exile in neutral Switzerland. There with the help of his friend Hermann Rupf he set up home in Berne. When war was declared he did not return to France and his property was confiscated, including a large number of canvases by the artists he was representing.
Picasso was particularly infuriated by the situation and had to make a legal case to regain possession of his unpaid-for artworks. When he did, he found that some of them had been damaged due to the damp storage conditions in the Rue de Rennes. Picasso felt that Kahnweiler should have arranged to let a French dealer take over his stock or at the very least have shipped it to the United States or to Switzerland. The ill-feeling this incident caused resulted in Picasso dismissing Kahnweiler as his dealer. They were later reconciled after the end of World War II.
Juan Gris also fell out with Kahnweiler when the dealer refused to let the penniless Gris sell his new work to other collectors during the interim. They were quickly reconciled when Kahnweiler agreed to a monthly salary of 125 francs a month. However in 1915 Gris also left Kahnweiler's stable.
While in exile in Switzerland, Kahnweiler wrote the first important critique of the Cubist movement he had husbanded, Der Weg zum Kubismus. He also studied philosophy at the University of Berne.
He returned to France where he remained a major and respected art figure until his death in Paris.