opposed it, arguing that it was Nazi racial theories that were the origins of the German invasion of the Soviet Union. The majority opinion was that Rothfels and Weinberg destroyed Seraphim's and Hillgruber's arguments. Indeed, Hillgruber himself did a volte-face and renounced his former thesis as mistaken. Later, in 1961, Rothfels took a strong stand against the American neo-Nazi historian David Hoggan who claimed that the outbreak of war in 1939 had been due to an Anglo-Polish conspiracy against Germany. Also in 1961, Rothfels assisted Weinberg with the publication of Adolf Hitler's Zweites Buch which Weinberg had discovered in 1958, and for which Rothfels wrote the introduction. Another area of interest for Rothfels was the expulsion of the ethnic German population from Eastern Europe after World War II. In the 1950s, Rothfels worked with Theodor Schieder, Werner Conze and other historians to produce the multi-volume Documentation of the Expulsion of Germans from East Central Europe. Many later prominent historians such as Martin Broszat, Hans-Ulrich Wehler and Hans Mommsen were involved in this project. Controversy In his lifetime and since his death, Rothfels has been a very controversial figure. Many see him as apologist for the anti-democratic German Right, and in particular, his attitude towards the Weimar Republic has recently been the subject of controversy in Germany. The historian Ingo Haar in his 2000 book Historiker im Nationalsozialismus called Rothfels an enemy of the Weimar Republic and a Nazi sympathizer. The historian Heinrich August Winkler has strongly criticized Haar, who had erroneously used a radio address Rothfels gave in 1930 praising Friedrich Ebert, Gustav Stresemann, and Paul von Hindenburg as great German leaders as a proof for Rothfels' support of Hitler. While Haar had implied the speech dates from 1933 and was addressed to Hitler after he took over power in Germany, Winkler verified the actual circumstances of the speech, which Rothfels repeated several times prior to 1933. Rothfels's critics contend that his planned 1933 radio address was too little, too late. Rothfels and his inner circle at Königsberg in the early 1930s are often referred to as the Königsberg circle (). Its most prominent members, apart from Rothfels himself, were his students Theodor Schieder and Werner Conze. Whereas Rothfels had to emigrate, Schieder and Conze joined the NSDAP. They were active in the field of Ostforschung, where they supported ideas such as 'dejewfication' (). After Rothfels' return the three became