"The period 950-1250 witnessed a fundamental and irreversible change in Europe. A persecuting society formed that may be seen as the origin and forerunner of the atrocities of the religious wars, the executions of the Reformation, even the Holocaust of the twentieth century. The isolation, repression, exile and attempted extinction of Jews, heretics and lepers involving a radical transformation in the relation betwen authority and people. 'Heretics and Jews,' he argues, 'owed their persecution in the first place not to the hatred of the people but to the decision of princes and prelates.'" -- From back cover.