Leonardus Johannes Stappers, C.I.C.M., was born on 6 June, 1919 in Blerick (Netherlands). After spending several years in the seminary, he was ordained as a priest in 1943 within the order known as the “Scheutists” (Congregatio Immaculati Cordis Mariae). He developed an early interest in African languages and, following a two-year programme of study at the School of Oriental and African Studies in London, obtained a degree in Bantu studies. As a missionary, he served as headmaster of a primary school in Ngongo (Kasaï/Belgian Congo) from 1948 to 1951, and from 1951 to 1957 he taught at the Jan Berchmans College in Kamponde. After returning to Europe, he completed his doctorate at KU Leuven in 1964 with a dissertation on the Bantu language Songye, and subsequently accepted academic appointments in Kinshasa (1964–1971) and Lubumbashi (1971–1974), where he taught and conducted research at both universities. In 1974, he was appointed to the Johannes Gutenberg University Mainz as the first Professor of African Philology (now African Languages and Linguistics), a position he held until his death in 1977.

The collection comprises a wide range of published and unpublished works, including draft sketches and manuscripts by Stappers, final theses written by some of his students, as well as various collections of African literature that he either recorded on his travels or received and preserved from fellow missionaries. Among these are important documentary works by the Belgian missionary Camille François Van Ronslé (* September 18, 1862 – † November 14, 1938). Many of these sources exist only in their current form and are not available at other library locations (worldwide).

Stapper’s work is primarily focused on the Bantu languages of the Democratic Republic of the Congo (formerly Zaïre). Of particular significance are his extensive and partly unique, unpublished works on the Bantu languages of the Luba group (L30), including Cilubà (Luba-Kasaayi) and other closely related languages. Among these are handwritten drafts for a planned Luba grammar, as well as several hundred unpublished Luba texts. His documentary work on languages that have so far been little or not previously described is considered especially valuable for the field of Bantu studies.

In addition to Stappers’ works, the archive also stores the final theses of his graduates from the Universities of Kinshasa and Lubumbashi. These include rare grammatical descriptions of a wide range of Congolese languages which, as far as is known, have remained unpublished to this day. They thus offer unique insights into numerous entirely undocumented language varieties.

Perhaps the most important part of the collection, however, consists of the unpublished, handwritten manuscripts of the Belgian missionary Van Ronslé, who, during his many years in what was then the Belgian Congo, dedicated himself extensively to documenting Bobangi, as well as a contact language that developed in the northern Congolese Iboko. These works are considered unique and of exceptional value, and have already been digitised by the University Library as part of the Gutenberg Capture initiative.

1. Eléments de la grammaire de la langue Bobangi (1899)
2. Grammatica Ibokoensis (1891, Berghe St. Marie)
3. Vocabularium Ibokoensis (estimated year of origin: 1891/92)

Equally noteworthy is the following manuscript, which is anonymous but is likely also attributable to Van Ronslé:

1. Lokota lo Bobangi [The Bobangi language] (anonymous, no date)

These are works that were lost for a long time, which are of great significance and importance for understanding the linguistic history of the DR Congo, particularly with regard to the development of the contact language Lingala, which is widely spoken today. The previously withheld writings on the precursor language of Lingala allow for the closure of a glaring and hitherto existing gap in historical linguistic research.

The rarity and, in some cases, uniqueness of the archive’s collection calls for linguistic, linguistic-anthropological and also literary engagement of the works and manuscripts; particularly given that the collection had been kept privately and remained inaccessible to the public for several decades by Dr Hans-Ingolf Weier, a former member of the institute. Following his death in 2020, the collection was transferred to the Institute (Stapper’s last place of work), where the value of the collection was quickly recognised by Junior Professor Nico Nassenstein and Dr. Anna-Maria Brandstetter. They have since advocated for the establishment of a publicly accessible archive from the private library, as well as for the safe preservation of the old and valuable manuscripts.

Thanks to funding from the Sulzmann Foundation, an initial six-month review of the material, as well as a preliminary sorting of the collections has already benn carried out by doctoral student Janika Kunzmann, M.A. With the support of Belgian colleague Prof. Dr. Michael Meeuwis, who significantly contributed to the discovery of the above-mentioned Van Ronslé manuscripts, the value of various manuscripts could be determined. His in-depth knowledge of the linguistic and research history of the region enabled the identification of numerous texts and their contextualisation. In the near future, further especially valuable and fragile documents are to be digitised in collaboration with the University Library Mainz and the Centre for Digitisation and Photographic Documentation (SDF), thereby not only preserving them but also making them accessible to a wider public. At present, the Luba collections in the archive are being reviewed and examined by expert Dr. Mpunga wa Ilunga, a former student of Stappers in Lubumbashi and a visiting professor at the Université de Mbujimayi in Kasai (DR Congo). A preliminary sorting and precautionary first digitisation is currently being under taken by Nico Nassenstein, in communication with the Lubaspeaking community in Brussels, Belgium.