When Nazi Germany invaded Poland in 1939, it aimed to destroy Polish national consciousness. As a symbol of Polish national identity and the religious faith of approximately two-thirds of Poland's population, the Roman Catholic Church was an obvious target of the Nazi regime's policies of ethnic, racial, and cultural Germanization. The author reveals in this book that the persecution of the church was most severe in the Reichsgau Wartheland, a region of Poland annexed to Nazi Germany. Here Catholics witnessed the execution of priests, the incarceration of hundreds of clergymen and nuns in prisons and concentration camps, the closure of churches, the destruction and confiscation of church property, and countless restrictions on public expression of the Catholic faith. The author also illustrates how some among the Nazi elite viewed this area as a testing ground for anti-church policies to be launched in the Reich after the successful completion of the war. Based on largely untapped sources from state and church archives, punctuated by vivid archival photographs, and marked by nuance and balance, this volume exposes both the brutalities and the limitations of Nazi church policy. The first English-language investigation of German policy toward the Catholic Church in occupied Poland, this compelling story also offers insight into the varied ways in which Catholics-from Pope Pius XII, to members of the Polish episcopate, to the Polish laity at the parish level-responded to the Nazi regime's repressive measures.