James Estes's work has made wide-ranging contributions to our understanding of the Reformation's effect on political authority. Including eleven essays and an appendix that span five decades, this compilation offerings a fitting overview to Estes's research. The chapters focus on three major figures of the magisterial Reformation: Johannes Brenz, Martin Luther, and Philipp Melanchthon. Collectively, the articles chart numerous connections between these three theologians and a fourth major thinker, Erasmus of Rotterdam. The overarching theme of the volume is the relationship between church and state broadly conceived. They discuss not only the theoretical arguments made by these four authors about the duties and prerogatives of secular authority, but they also engage with how Brenz, Luther, and Melanchthon sought to turn those theories into reality through the institutionalization of religious reform. Estes's analysis of the interplay between theory and action in the world represents one of the most valuable contributions of these articles and serves as a crucial reminder of the benefits of combining a study of theology with political and social history. The selection of essays is well-balanced chronologically, stretching from the 1510s and Luther's first attempts to grapple with the role of secular authority in supporting church reform to the Interim Controversy of the late 1540s and early 1550s. The articles, most of which were previously published individually in journals or edited volumes and have undergone light revision for inclusion here, are organized in the order in which Estes wrote or published them, which allows the reader to see the development of various strands of analysis over the courses of several decades. Alongside the previously published articles, the collection includes two pieces never published before: an article on Brenz and the Interim in the duchy of Württemberg, and an English translation of Melanchthon's important 1539 tract, De officio principum. The book also includes several color plates that complement its themes. Taken together, the articles serve as a wonderful introduction to the breadth of Estes's research and offer a fitting tribute to his career.