This study of two important German–Jewish collectors who settled in Paris, after 1866, Maurice (1839–1906) and Rodolphe (1845–1905) Kann, examines their place in French society. Based on unpublished archives, in particular the discovery of their wills (Archives Nationales, Paris) and their correspondence with Wilhelm von Bode (Berlin), it helps us to understand the evolution of the brothers’ collections and their practice of donation. Paradoxically, these two collectors escape any classification. Are they collectors? Are they patrons? They appear on the fringes of the group of collector figures of the late 1800s, and their activities show that the frontier between personal pleasure and speculation is porous. The article also raises the question of the role of dealers in the construction of a business focused on collection at the fin-de-siècle.