The Heidelberg Manifesto of 17 June 1981 was signed by 15 German university and college professors to warn about the "infiltration of the German people" and of the "Überfremdung" (roughly, 'over-foreignisation') of German language, culture and 'Volkstum' (roughly 'national/ethnic character'). It is widely deemed to have been the first time after 1945 that racism and xenophobia were publicly - albeit controversially - legitimised by academics in Germany.

The manifesto's primary initiators were Theodor Schmidt-Kaler (German pronunciation: [ˈteːodoːɐ̯ ˈʃmɪtˌkaːlɐ]; born 8 June 1930 in Seibelsdorf, Bavaria), an astronomer and self-taught demographer of Bochum University, and Helmut Schröcke (German pronunciation: [ˈhɛlmuːt ˈʃʁœkə]; born 18 June 1922 in Zwickau, Saxony), a mineralogist of Munich University. Both professors already stated their main theses in advance which were then adopted into the manifesto. In 1980, they wrote:

Today, the term 'Volk' can be defined scientifically: 'Völker' are, cybernetically and biologically, living systems of a higher order with distinct systemic properties that are passed on genetically. This also applies to the non-physical properties which are inherited just like the physical ones (the milieu theory is scientifically wrong)."

Our problem are not the guest workers as such but their Asiatic component. [...] Leaving out the special problem of Southern Italy, we can conclude that, according to their fertility, their cultural, sociological and religious context, we can expect the acculturation of the guest worker families coming to us from the European area. [...] None of this applies to the Asiatics."

The original version of the Heidelberg Manifesto was penned by Schröcke on 17 June 1981 and signed by 15 professors in total. Next to Schmidt-Kaler and Schröcke, the pertaining professors were: Manfred Bambeck (Frankfurt U), Rolf Fricke (Karlsruhe IT), Karl Georg Götz (Stuttgart U), Werner Georg Haverbeck (Collegium Humanum), Joachim Illies (MPI of Limnology), Peter Manns (Mainz U), Theodor Oberländer (retired Minister of Expellees), Harold Rasch (Frankfurt U), Franz Hieronymus Riedl (from Austria), Heinrich Schade (Düsseldorf U), Kurt Schürmann (Mainz U), Ferdinand Siebert (Mainz U), and Georg Stadtmüller (Munich U).

In this original version (which at first was not planned to be presented to the wider public), there was e.g. this passage:

With great concern we observe the infiltration of the German people [i.e. Volk] by the influx of many millions of foreigners and their families, the over-foreignisation [i.e. Überfremdung] of our language, our culture and our national character [i.e. Volkstum]. [...] The integration of large masses of non-German foreigners is therefore not compatible with the preservation of our people at the same time, and leads to the well-known ethnic catastrophes of multi-cultural societies. Each people, the German one as well, has a natural right to the preservation of its identity and character in its residential territory. Respect for other peoples mandates their preservation, but not their amalgamation ('Germanisation').

By the end of 1981, the manifesto's original version was published in three far-right magazines at once: the Deutsche Wochenzeitung [German Weekly Newspaper], Nation & Europa, and Deutschland in Geschichte und Gegenwart [Germany in Past and Present]. Furthermore, this version was distributed at the same time as a flyer in several university towns. Thereby, students in Bonn and Munich became aware of this and informed the mainstream media.