The Hahnloser Collection was created in the early twentieth century in close friendly exchange between the collectors Arthur and Hedy Hahnloser-Bühler and their famous artist friends. The book provides with some 120 works an overview of this unique international collection of Modernist art as well as illustrating its exemplary cultural-political character.

The catalogue sheds light on the collectors' close contact with their artist friends including Pierre Bonnard, Ferdinand Hodler, Henri Matisse and Felix Vallotton. It provides an insight into unknown aspects of the artists' lives, their creative work and the motivation and passions of the collectors themselves. Today the collection is largely in the possession of the collectors' heirs or has been donated to the art museums of Bern and Winterthur.