In this powerful investigation, Kertzer argues that the Roman Catholic Church's role in the historical hatred and persecution of Jews in Europe helped make the Holocaust possible. Focusing on the popes, cardinals, bishops, priests and the laity, who were convinced that they were doing God's work, his dispassionate narrative reveals how traditional Catholic forms of dealing with Jews were transformed into modern anti-Semitism. Unholy War strongly contradicts the Vatican's own account of its history. Compellingly written, it sheds light on a remarkable and disturbing story that until now has remained hidden. 'The material is dynamite' THE TIMES 'Riveting' NEW YORK TIMES 'Powerful and shocking' TIMES LITERARY SUPPLEMENT 'Devastating' SCOTSMAN