Archives occupy a special place in academic research. The aim of the paper is to present sources for research on the functioning of the Regency Council in the resources of the Archives of New Records in Warsaw (AAN). The documentation collected in the AAN is dispersed (it is stored in several archival units: the Civil Cabinet of the Regency Council, the Presidium of the Council of Ministers, the Ministry of Provisioning, the Ministry of Foreign Affairs, and private files) and most often complements each other. The aforementioned documents allow for the presentation of both the organization of governments, their personnel, as well as the analysis of the “governing process” and the connections between the Regency Council and subordinate institutions, social organizations, and the occupation authorities.