Theodor Ahrenberg (born March 2, 1912 in Gothenburg, Sweden; died June 21, 1989 in Vevey, Switzerland) was a prominent collector of 20th-century art. In 1962, his first extensive collection, featuring works by some of the most important artists of the 20th century, including Matisse, Picasso, Chagall, and others, was expropriated by the Swedish state. Following this, Theodor Ahrenberg relocated to Switzerland and established an artist residency on his estate in Chexbres. This marked the beginning of his second collection, with over 120 artists, including Christo, Arman, Lucio Fontana, Enrico Baj, Mark Tobey, Jean Tinguely, and Niki de St. Phalle, visiting the studio in Chexbres between 1963 and 1977. Ahrenberg was able to preserve and expand the entire archive of his first collection in Chexbres, which developed into a highly significant archive that highlights the very personal relationship between Ahrenberg and these artists. This archive includes numerous letters, drawings, photographs, documents of the exchange with the aforementioned artists and Theodor Ahrenberg, as well as other evidence of the Ahrenberg family's collecting activities. The purpose of the association is to make this important and valuable archive accessible to the public, to preserve the historically significant documents, and to make them available to interested parties. The association promotes the recognition of the collection, organizes and supervises exhibitions and presentations in Switzerland and abroad, and makes the collection's holdings available for the printing of literary texts, reprints of out-of-print literary and artistic works, catalogs, scores, etc. The association also fosters contact between its members and museums, other public and private cultural institutions, artists, domestic and foreign art collectors, and other interested representatives of the art scene. The association's activities focus on the cultural city of Basel, as well as the whole of Switzerland and abroad. The association operates exclusively for non-profit purposes and does not pursue any commercial or self-help goals. The organs are active on a voluntary basis. The association acts entirely charitably and does not pursue any self-interest. The collection is made accessible solely to the general public.