Rijksarchief in België, CEGESOMA / Archives de l'État en Belgique, CEGESOMA

The Centre for Historical Research and Documentation on War and Contemporary Society (CEGESOMA) is a federal research institution that examines the wars and conflicts of the twentieth century and their impact on Belgium. Founded in 1969, it collects archives and documentation, carries out research and organises academic and public events. The centre's documentation is searchable through its online catalogues and can be consulted in the public reading room of Centre's historic Art Deco building at the Square de l'Aviation in Brussels. In 2016, Cegesoma was integrated into the Belgian State Archives.

Since the first of January 2016, the institution is the fourth Operational Directorate (OD4) of the State Archives (see programme act of 26 December 2015 and royal order of 23 May 2016) . It is led by an operational director, who is supported by the specialised Scientific Committee of the CegeSoma

The archive collection of the CEGESOMA consists of 1,356 meters of paper records, 165 filing card boxes and 4,675 microfilms from the period 1914–2000. The collection includes personal archives, archives of private organisations, of collaborators and collaborationist movements, of resistance fighters and resistance organisations, of official institutions and services that existed only between 1939 and 1946 (based under the terms of an agreement with the General State Archives) and of microfilms and photocopies of foreign archival collections. Some collections are already accessible online. The library comprises about 62,000 books and brochures, more than 4,000 periodicals and newspapers and a large collection of press cuttings. Originally, the collection focused on the history of the Second World War. The library of the Information Service of the Belgian Government in London and the collaborationist press which, at the Liberation, was seized by the military justice authorities provided the basis for the collection. The gap in the collection that existed when the Centre was created in 1969 is gradually being filled, especially through donations. At the same time, the library has systematically acquired newly published works on Belgium and the Second World War. From the 1990s onwards, the library has also focused on other areas and fields of interest. The Centre acquires publications on political and cultural world history of the short 20th century, from the First World War to the 1970s. Within this large field, priority has been given to themes with a relevance to contemporary conflicts such as nationalism, ethnicity, racism, migration, communism, the extreme right, colonisation/decolonisation and genocides. These are also the themes that determine the Centre's acquisition policy of current national and international periodicals (more than 65 subscriptions). The collection of periodicals and newspapers which permanently is in permanent expansion thanks to donations and exchanges is particularly varied. “Popular” weeklies as well as periodicals of political parties, social organisations and action groups are all included in the collections. Moreover, the Centre holds the largest collection of clandestine papers in Belgium. CEGESOMA has an audiovisual department comprising photographic archives, poster and videotape collections, sound documents and interviews.

Pallas, the online catalogue of CEGESOMA, allows the reader to search the archives, the library and the audiovusual collections of the Centre. The following collections are already accessible :

• The archive collections: all descriptions on the fond level and higher, and all the inventories. Some archive collections have already been digitized

• All the descriptions of the manuscripts

• Nearly all the descriptions of the books and brochures

• 90% of the descriptions of the periodicals

• All the descriptions of the press cuttings

• The descriptions, but also the digitised reproductions of all the tracts (14,000 images)

• The descriptions, but also the digitised reproductions of approximately 250,000 photographs

• The descriptions, but also the digitised reproductions of approximately 60% of the poster collection.

All the descriptions of the photographs are available in French and Dutch. This is also the case for the highest levels of archive descriptions; other descriptions are written in the language of the person responsible for cataloguing them.