In 1955, Barnes first met David Hoggan , and played a key role in helping Hoggan adapt his 1948 PhD dissertation, The Breakdown of German-Polish Relations in 1939: The Conflict Between the German New Order and the Polish Idea of Central Eastern Europe, into his 1961 book, Der erzwungene Krieg ( The Forced War ). It was "based on, but quite different from, the dissertation", and Hoggan blamed Britain and Poland for World War II.  In 1963, Barnes self-published a pamphlet, "Blasting the Historical Black-out", in which he offered some praise for A. J. P. Taylor's 1961 book, The Origins of the Second World War .  Barnes said that he thought Hoggan's book was better than Taylor's.  In "Blasting the Historical Black-out", Barnes referred to the "alleged wartime crimes of Germany" and wrote that, "Even assuming that all the charges ever made by the Nazis by anybody of reasonable sanity and responsibility are true, the Allies did not come off much, if any better".  Barnes wrote further that the suffering by ethnic Germans expelled from Czechoslovakia and Poland after World War II were "obviously far more hideous and prolonged than those of the Jews said to have been exterminated in great numbers by the Nazis." 
The feudal system of that time was obsessed with family relationships, deliberately brought about by arranged marriages between families of the same land-owning class, to the point eventually of considerable inbreeding. It was not an age of women’s rights – daughters married who they were told to marry and that was that. The aim was to ensure continued inheritance of land, which was the only way to have any wealth and power. The alternative was destitution and poverty for one’s descendants. This helps to explain to modern minds why these possible family links are such important clues to medieval genealogy.
During the "Goldhagen Controversy" of 1996, Kershaw took the view that his friend, Hans Mommsen , had "destroyed" Daniel Goldhagen 's arguments about a culture of "eliminationist antisemitism" in Germany during their frequent debates on German TV.  Kershaw wrote that he agreed with Eberhard Jäckel 's assessment that Hitler's Willing Executioners was "simply a bad book".  Though Kershaw had little positive to say about Goldhagen, he wrote that he felt that Norman Finkelstein's attack on Goldhagen had been over-the-top and did little to help historical understanding.  However, Kershaw later went on to recommend Norman Finkelstein and Ruth Bettina Birn's extremely critical assessment of Goldhagen 's book, A Nation on Trial: The Goldhagen Thesis and Historical Truth ; stating that "Finkelstein and Birn provide a devastating critique of Daniel Goldhagen's simplistic and misleading interpretation of the Holocaust. Their contribution to the debate is, in my view, indispensable." [ citation needed ]