The heart of the collection owes its existence to a number of generous gifts and bequests, including those of Jeanne de Sépibus, Yvonne von Wattenwyl, and Jenny & Diane de Margerie.
They include correspondences (letters from Rilke and others), manuscripts (Quatrains Valaisans, The Duino Elegies, Le Noyer), books, photos, paintings, engravings, and sculptures. Over the course of decades, thousands of books, articles, and translations in various languages have been added to the original collection. The library catalogue has grown and includes approximately 13,750 entries at present.
The collection was substantially increased by the acquisition of two significant private collections. The Foundation acquired Manfred Gahl’s collection in 1995 and in 2000, of Dr. Karl Klutz’s meticulously curated library.