The territorial complexity of Mark Brandenburg in the sixteenth and seventeenth centuries is matched by an equally convoluted religious history. Uwe Folwarczny's book examines the reign of Joachim Friedrich, Elector of Brandenburg from 1598 to 1608, emphasizing the ruler's practical, collaborative, flexible approach to governance at a challenging time of political upheaval in a polarized confessional climate. Joachim Friedrich endorsed the Lutheran reform program initiated by his grandfather, Elector Joachim II (1535-1571), and continued by his father, Elector Johann Georg (1571-1598), who introduced an orthodox Lutheran Kirchenordnung for Brandenburg in 1572. Lutheranism was well established in Brandenburg when, upon Joachim Friedrich's death, his son, Elector Johann Sigismund (1608-1619), converted to Calvinism and attempted to bring the rest of Brandenburg along with him, with mixed success. Andreas Stegmann's Die Reformation in der Mark Brandenburg (2017) lays out the history of the early Reformation in Brandenburg, and Bodo Nischan's Prince, People, and Confession: the Second Reformation in Brandenburg (1996) picks up the Calvinist narrative, but Folwarczny offers an impeccably researched, in-depth study of the period in between, just before one reform regime tipped into another.

Joachim Friedrich was “decidedly Lutheran”: he firmly abolished all remaining Catholic ceremonies and declared his opposition to “Calvinists, Antinomians, and all other Errors” (323), while establishing Lutheran orthodoxy in Brandenburg's church and school administration. But Brandenburg bordered many Calvinist territories, and Joachim Friedrich welcomed Calvinists into the highest levels of his government, including the Secret Council he established in 1604 to guide him in political matters both internal and external. Joachim Friedrich had extensive experience with church administration before his elevation to the status of Elector: his grandfather Joachim II had assigned him to become the “secular” bishop of the diocese of Havelberg in 1554, when he was a child of just seven years old. By the time he was fourteen, Joachim Friedrich also controlled the dioceses of Lebus and Brandenburg, and later became the administrator of the Erzstift Magdeburg. Even as confessional tensions increased inside and outside Brandenburg, Folwarczny presents Joachim Friedrich as a mediating figure, attempting to maneuver between confessions and forge a “middle way” (125). He continued this approach into his decade-long reign as Elector, where he attempted to defuse the growing confessional conflict in the Empire while responding to dynastic crises, the dissolution and creation of Protestant military alliances, and the need to establish religious order within Brandenburg. Joachim Friedrich's Realpolitik approach to governing and his willingness to take advice from Calvinists have led some scholars to question whether he was truly a strict and zealous Lutheran like his father, or maybe a “secret Calvinist” himself (349).

Perhaps the most remarkable thing about this study of Joachim Friedrich is that it does not focus only on the Elector. Folwarczny employs the methods of collective biography to illuminate the complex interplay of personalities that influenced political and religious decisions at court and throughout the territory of Brandenburg. The book's final section offers complete biographical essays on twenty-two different officials who played a role as advisors to the Elector or administrators in his regime. Whenever any of these individuals is mentioned in the main text, an arrow symbol alerts readers that extensive information about this person is available in a separate section. Though it is somewhat inconvenient for a reader to pause in the narrative and flip to the back of the book, this structure makes it possible to obtain a deeper understanding of the men involved at key decision points in the Elector's reign, and thus a fuller, more nuanced picture of the process by which Joachim Friedrich operated his regime. Integrating so much biographical information into the main text would make it next to impossible to maintain an argument while offering full detail about the individuals involved. Folwarczny's decision to place discrete biographical essays in their own section avoids this problem, while allowing sufficient space for a complete and holistic assessment of each person's influence, life, and work, not limited by the need to resume the thread of the larger narrative or argument. Folwarczny's collective biography approach to understanding the tensions, challenges, and decision-making process during Joachim Friedrich's rule make this a particularly useful book for anyone interested in the inner workings of an early modern princely court.