Historians need historical sources. Some historical fields have more sources than others. It is rumored that in some ancient historical sub-fields it is possible for the historian to read every extant primary source, but no historian of twentieth-century German religious history has accomplished this feat. Helge-Fabien Hertz has come to the aid of historians of religion in the National Socialist era with his expansive Evangelische Kirchen im Nationalsozialismus: Kollektivbiografische Untersuchung der schleswig-holsteinischen Pastorenschaft (Protestant Churches under National Socialism: A Collective Biographical Study of the Schleswig-Holstein Pastorate). This unprecedented work offers the largest case study of the clergy of a single German regional church in the Third Reich. Hertz's three-volume work examines the collective clergy of the Schleswig-Holstein Church from 1930 to 1945. Hertz provides a scrupulous examination of over 700 pastors. He analyzes their actions along a broad spectrum of compliance to nonconformity vis-à-vis the Nazi state. He identifies ten prototypical personality types of Nazi conformity/nonconformity through the analysis of 122 types of action.

This work is an encyclopedic examination of 729 pastors from Schleswig-Holstein and their responses to National Socialism in the Third Reich. Hertz draws from various national, state, city, and regional archives as well as published sermons and family collections. He provides in these three volumes nearly 1,800 pages of material. Originally a dissertation at Christian-Albrechts Universität in Kiel, Hertz developed this work into a data goldmine for future research. This is truly a first of its kind source in terms of its ambitious approach to examining and classifying an entire regional Church's pastorate. Furthermore, Hertz's voluminous data are available online through the support of various Church and research entities in Schleswig-Holstein. Interested researchers may access the data at pastorenverzeichnis.de. The website includes pages for all 729 pastors including: biographical data, church-political associations (e.g., Deutsche Christen or Confessing Church), political affiliations, parish information, sanctions against pastors, and recommended sources and literature.

Hertz employs ten personality types to display the range of responses to National Socialism within Schleswig-Holstein. He examines a prototypical pastor for each type. These types range from the Nazi activism of Boye Gehrckens to the victimhood of Ernst Gloyer. These ten prototypes include pro-Nazi positions, anti-Nazi positions, and approaches that are difficult to define (e.g., Peter Höhnke is listed under “Synchronous and Diachronic Mixed Forms”). Hertz displays care to represent the full range of divergent data through his selection of ten prototypes. Some clergymen like Walter Rustmeier do not fit neatly into previous historiographical dichotomies – as evidenced by Rustmeier's pro-Nazi activism paired with his defense of church autonomy. Hertz further demonstrates a commitment to rigor and transparency by the inclusion of a tenth prototype of “Not Assignable.” He includes in his data (and online database) pastors that do not fit cleanly into his categories.

Hertz employs 122 types of action in his data in Volumes Two and Three. These types of action form the basis of his empirical assessment of the level of support or dissidence relating to National Socialism. Volume Two addresses eighty-one types that relate to Nazi conformity, and Volume Three gives forty-one types that relate to nonconformity. These 122 factors include membership in Nazi organizations, “verbal praise of Hitler,” “condemnation of the Weimar Republic,” “Hitler salute in internal church correspondence,” Confessing Church membership, “protest against the hostility to the church of individual Nazi officials,” voluntary resignation from the NSDAP, and state-imposed sanctions against pastors. These volumes provide a treasure-trove of data for researchers. Hertz gives a wealth of graphs detailing political party membership, generational data of Schleswig-Holstein clergy, church-political group membership, etc. This three-volume set includes over 300 graphs.

Categorizing people is never simple. Creating typologies of Christian engagement in National Socialist Germany is not easy. Helge-Fabien Hertz is to be commended for his ambitious work researching, analyzing, and categorizing over 700 individuals. He displays thoughtfulness and care in his extended explanation of his methodology and the various difficult decisions of categorization. Some readers will not agree with particular decisions (e.g., where a given type of action belongs on the spectrum of nonconformity to resistance), and other readers may not be interested in the lengthy methodological argumentation. This work is sure to inspire further research and serve as a valued resource for future historians of German religious history. Although it is at a high price point for individual readers, it would be a beneficial purchase for institutional libraries.

Hertz excels in demonstrating the heterogeneity of the German Protestant pastorate in Schleswig-Holstein. This provides a compelling case study to support the work of historians who in the past three decades have challenged facile and exculpatory dichotomies surrounding the memory of the German Protestant experience in the Third Reich. Historians have long known (and argued) that Dietrich Bonhoeffer's resistance to the Nazi regime was not representative of German Protestantism writ large. Hertz demonstrates that – at least in Schleswig-Holstein – German Protestant pastors were more likely to be sympathetic to National Socialist Germany, albeit with a commitment to the autonomy of the churches.