Over more than six decades the institute has performed notable and internationally recognised geodetic basic research, and today the acronym DGFI is well-known in the geoscientific community all over the world. The institute is strongly cross-linked with other institutions and has continuously been involved in various national and international activities. Intensive collaborations exist in particular in the frame of the international scientific organisations IUGG (International Union of Geodesy and Geophysics), IAU (International Astronomical Union) and IAG (International Association of Geodesy). DGFI recognises the outstanding role of the IAG services for science and practice, and co-operates in these services as data, analysis and research centres. Scientists of DGFI have taken leading positions and supporting functions in IAG's Commissions, Services, Projects, Working and Study Groups, and in the Global Geodetic Observing System (GGOS). Furthermore, DGFI staff is prominently involved in the management of international scientific organisations, e.g., in the European Geosciences Union (EGU) and in the International Astronomical Union (IAU). DGFI also participates in research programmes and bodies of the European Union (EU) and the European Space Agency (ESA). It co-operates in several United Nations' (UN) and intergovernmental institutions and activities.