Born in Paris and educated for a time in England, César Mange de Hauke moved to the United States in 1926, and joined the New York branch of the Seligmann galleries. The firm of De Hauke & Company was set up by Germain Seligman c. 1926 with his personal funds, to deal in more modern art than the Seligmann firm had traditionally done. Exhibitions of late 19th century French painting, Bonnard, and Modigliani were held under the auspices of De Hauke & Co, which was eventually intergrated completely into the New York branch of the Seligmann firm. At that time, c. 1931, de Hauke resigned from Seligmann. He bequeathed a collection of French drawings to the British Museum, and also made bequests to the Musée de Versailles and the Musée du Louvre. Records of de Hauke's activities related to his time with Seligmann are at the Archives of American Art.
Seligman, Germain. Merchants of Art: 1880-1960, Eighty Years of Professional Collecting. New York, 1961.
The César Mange de Hauke Bequest. The British Museum, London, 1968.