The germ cell of the current Theodor Fliedner Foundation was the Pastoralgehülfen- und Diakonenanstalt (Pastoral Help and Social Welfare Association) founded by the Protestant Pastor Theodor Fliedner in Duisburg in 1844, and which only four years later was converted into an independent foundation, the Diakonenanstalt Duisburg (Social Welfare Association Duisburg). It is the second oldest such Social Welfare Association in Germany.
The Diakonenanstalt Duisburg was a training centre for male deacons. It harked back to the inspiration and example of the Hamburg pastor and founder of the Innere Mission, Johann Hinrich Wichern, who had founded the famous Rauhe Haus in Hamburg as a home for young neglected males, and trained male helpers for this purpose. The goal of the Diakonenanstalt was the education and appointment of auxiliary deacons as house fathers in homes as well as administrators, medical attendants and employees in public social work. The current Diakoniegemeinschaft e.V. evolved from this work.
In the course of time, the Diakonenanstalt Duisburg continually took over new fields of work: nursing, child welfare, orphanages in East Prussian Masuria, care of the poor, inner mission, work in prisons, help for alcoholics, and also combating the cholera, smallpox and typhus epidemics which afflicted the Rhineland, Westphalia and East Prussia in the end of the 19th century. The work locations extend beyond the borders of Europe to Chile, North America and India. In the First World War, the number of these social welfare associations and branch facilities grew, scattered over the entire "German Reich". Some of these facilities still belong to the foundation today. Important impulses came from Haus Siloah (1879), probably the oldest addiction clinic in Europe for work with addicts. Today it belongs to the Fliedner Hospital Ratingen Lintorf. All the buildings of the Duisburg foundation were destroyed in World War II. The Mülheim facilities were completely rebuilt.
The current character of the foundation is characterized by the new start launched in the early 19080s with the appointment of Prof. Klaus D. Hildemanns as Executive Director. Since then the institute has been remodelled into a modern social welfare establishment. With the end of the GDR, elderly and handicapped facilities were taken over and also built in the new German federal states. Today the foundation plays an exemplary role and is active in many areas: working with the disabled, in geriatric care, in psychiatry and psychotherapy as well as education, research and teaching. A special feature is the turning of conventional homes into integrated living and life forms. Another feature is the academic orientation of the foundation, expressed in several cooperations with universities.
In July 2001, the foundation received a modified statute. Since then, in accordance with its supraregional orientation, it belongs to the Protestant Church of Germany and is thus a member in all state protestant churches in areas where it is active.