Erich Keyser born 12. October 1893 in Danzig (Gdansk); died 21st February 1968 in Marburg was a Nazi activist and far-right nationalist historian connected with the anti-Polish ideology of Ostforschung and racist Volkisch movement. He supported German expansion in Central and Eastern Europe and was involved with ethnic cleansing. After the war he exploited the Cold War conflict to support interests of German nationalism and chauvinism in history writing.
In 1926 he created the State Regional Museum of Danzig History in Danzig-Oliva which he led till 1945 and which was later responsible for pursuing studies on direct requests by SS Reichsfuhrer Heinrich Himmler
Keyser also wrote in the infamous 1926 collection German Settlement Land in the East, which aimed to justify German claims to Eastern Europe and was part of emotional-ladden narrative writing that idealized the concept of Drang nach Osten
Among Keyser's key views was the desire to classify the historical nature of the population "according to physiological and psychological characteristics of racial make up of the population and its groups". In such studies he included psychological study of national character traits which led Keyser to support Rassenforschung(racial studies). He was especially interested in the "racial categorization of the current population of Germany and in the racial classification of psychological remains from the the centuries of the past". He considered the Germans the only representatives of hisorical life in Prussia and supported the volkich movement . Keyser imagined a racial and biological "essence" uniting Germans throughout history that supported irredentism of German nationalists. In his view the German "volk" needed to expand or perish. Like other historians from the volkisch movement he expressed overt racism and anti-semitism
In 1933 Erich Keyser joined NSDAP and soon became a virulent Nazi, active in supporting the Nuremberg decrees on race In 1938, Keyser openly placed the history of the are alongside Vistula river at the service of political ideology. With his concepts of so called "Weichselland" he created a myth of a historical region that never existed. In addition he tried to prove a continuous Germanic settlement of this region, using such ideas as Germanic "Norsemen", "men of the Nordic race" which he claimed infused the region with "unified characteristics". Another basic principle of his work was the construction of social and racial opposition between Germans and the Jews since Middle Ages.
Second World War
He was tasked with directing a research unit for regional and ethnic studies that was founded in 1939. This unit was linked to NOFG( "Die Nord- und Ostdeutsche Forschungsgemeinschaft") headed by Nazi Albert Brackmann and dedicated to the cause of ethnic reallocation of land in eastern territories. Alongside other Nazis he was responsible for planning and implementing of re-population policies in territories occupied Nazi Germany  and contemplated ways in which Poles unsuitable for Germanization could be efficiently removed in quick manner
Keyser was directly involved in Germanization attempts against Polish population in territories Nazi Germany annexed from Poland and formed in the so called Danzig-West Prussia region. In autumn 1940 Keyser attended the conference on History of Population in Berlin representing Office of Regional Studies in Danzig, alongside other leading Nazi scholars such as Hermann Aubin and Theodor Schieder. Part of Keyser's report concerned a project regarding germanizing names in territories annexed from Poland which were formed into Reichsgau's, while another was concerning history of population along Vistula River in order to assist with future population policy measures. Keyser along with other Nazi researches worked on compiling the German National List (Deutsche Volksliste DVL), and calculated that approximately 30,000 families Polish should be Germanized.
Despite the war, Keyser continued to expand his studies, by increasing the number of pages in his book about population history and adding in second edition in 1941 such section headings as "What is the Natre of the German People", "People and Population". A new section called "People and Race" was introduced in third edition of 1943, while section "Aliens in Germany" discussed "the first appearance of the Jews", "National Socialist population policy" and "the immortality of the German people".
In 1943, Keyser supported involvement of German historians and researchers in Nazi population policies and idea of connection between studies of "race" and demographics stating that "The will of the German people to cleanse itself of undesirable racial components" was the driving force behind such actions and in 1944 when Nazi Germany was losing the war praised Adolf Hitler in Nazi magazine "Wille and Macht"("Will and Power") stating that "The victory of the German troops of all Germanic tribes under the leadership of Adolf Hitler banished, in autumn 1939, the ghost of Versailles"  
By April 1944 Keyser started working together with Institute for Racial Studies of the Danzig medical academy where he carried out "ethnic and racial investigtions" on German colonists located in camps near the city and started working on studies regarding Kashubians.
Like other racist and nationalist ideologists of the Nazi era, Keyser managed to enter post-war academic scene in West Germany without serious obstacles, and like others he adopted his views from the Nazi era into rhetoric fitting Cold War  He outlined new objectives of German Ostforschung in 1952 in order to legitimize traditional German chauvinism by depicting Germans as bringers of order and development in Eastern Europe in concert with other European nations, this attempt had obvious connections to the past and tried to put Germans and Western community against undefined "East" He became responsible for the Herder Institute placing its work into the context of Ostforschung and openly declaring that its mission is to change the map of Europe and Germany, stating "Germany does not end at the Elbe, Oder or at Vistula"; the Institute openly and proudly demonstrated its continuity with past research under Nazi regime Only after his death the Herder institute gradually begun to escape from ethnocentric study of history and started studying ethnic groups in the region on more equal basis.
- Alexander Pinwinkler: Volk, Bevölkerung, Rasse, and Raum: Erich Keyser´s Ambiguous Concept of a German History of Population, ca. 1918-1955, in: Ingo Haar/Michael Fahlbusch (eds.), German Scholars and Ethnic Cleansing 1920-1945. New York-Oxford: Berghahn-Books 2005, 86-99.
- Rocznik gdański - Tomy 28-30 - Page 316 1970 - Wśród nich figuruje znany już w okresie międzywojennym z nienawiści do Polaków dr Erich Keyser.
- The Conquest of Nature David Blackbourn page 293, Random House 2007
- Germans, Poland, and Colonial Expansion to the East: 1850 Through the Present Robert L. Nelson Palgrave Macmillan, 15 Jan 2009, page 153
- The Other Prussia: Royal Prussia, Poland and Liberty, 1569-1772 - page 4 Karin Friedrich - 2006 Erich Keyser in Danzig supported the volkisch idea of history and considered the 'German people the real (and only) representative of historical life' in Prussia.
-  Other articles treat a variety of topics. Alexander Pinwinkler examines the völkisch historian Erich Keyser and his concept of Bevölkerungsgeschichte. Keyser imagined a racial and biological "essence" that united Germans across the ages and that justified their irredentist aspirations
- German Scholars in Exile: New Studies in Intellectual History - Page 58 Axel Fair-Schulz, Mario Kessler - 2011 "and he did not share the belief of radical historians such as Erich Keyser that the German Volk must expand or die".
- Paths of Continuity: Central European Historiography from the ... - page 7 Hartmut Lehmann, James Van Horn Melton - 2003 The unwholesome features of folk history, especially the overt racism and anti- Semitism of some of its leading adherents (for example, Adolf Helbok and Erich Keyser), make it hard for us today to see the movement in any other than a negative light
- Paths of Continuity: Central European Historiography from the ... - Page 286 Hartmut Lehmann, James Van Horn Melton - 2003 Erich Keyser, professor of history at Leipzig and an outspoken advocate of folk history (also a virulent Nazi who became known for his vocal support of the Nuremberg decrees on race)
- Writing national histories: Western Europe since 1800 - page 186 Stefan. Berger, Mark Donovan, Kevin. Passmore - 1999 "Hans Koch, Erich Keyser, Walter Kuhn, Manfred Laubert, Theodor Oberlander, Peter Heinz Seraphim and Hans Uebersberger were actively involved in planning and implementing the so-called 'repopulation' (Uinvolkung) of German, Polish, Jewish and other ethnic groups in occupied territories."
- Przegląd historyczny, Volume 97, Issues 1-4 Państwowe Wydawn. Naukowe, 2006 page 204
- Deutsch-polnische Hefte - Volume 3 - Page 653 1960
- Działalność naukowa i rola polityczna katedr filologicznych Politechniki Gdańskiej w latach 1925-1944 Michał Cieśla (prof. nadzw. dr.) page 12 Wydawn. Morskie, 1969 -
- Germany Turns Eastwards : A Study of Ostforschung in the Third Reich by Michael Burleigh page 29
- The Lost German East: Forced Migration and the Politics of Memory, 1945-1970 page 70, Cambridge University Press Andrew Demshuk - 2012
- Michael Burleigh Cambridge University Press, Germany turns eastwards: a study of Ostforschung in the Third Reich, Volume 8, Part 1991 page 315 "The objectives of the new German Ostforschung were outlined by Keyser in 1952. Necessity and sense of duty had compelled them all to begin anew. The German people were duty bound to study some seven hundred years of their history in the East the decisions of Yalta and Potsdam reflected an unknowning of German history.Narrow chauvinism was to be replaced by a sense of a European community to which the peoples of the East belonged. In practice this meant that the Germans had brought Christianity, cultural improvement, political order and economical development to the East in collaboration with other European nations. This internationalizing of traditional German chauvinism barely concealed the legacy from the past.A Western community of interest, juxtaposed against an undefined 'East', was apparent in much of the historical work produced by Ostforscher(...)
- The Quest for the Lost Nation: Writing History in Germany and ... -page 224 Sebastian Conrad - 2010 == page 175 Erich Keyser also consciously placed the Herder institute's work into the context of the Ostforschung tradition, which after 1945 was represented as a decidedly European project