Born in Poland but active for most of his life as a Reformed church leader in western Europe, John a Lasco is primarily remembered by modern-day students of the Reformation for his role in leading the foreign Protestant exile community out of England after the accession of Mary Tudor in 1553. Yet, as Michael Springer points out in his monograph, Lasco not only provided practical leadership to his community in times of crisis, but also laid out his vision for church order in his writings, especially in his Forma ac ratio. This work, published in 1555, described in detail how church services should run, how leadership positions in the church should be filled and how church discipline was to be administered. Springer's in-depth analysis of this work is preceded by a helpful overview of Lasco's life and career, and is followed by an assessment of the impact of the Forma ac ratio on the course of the Reformation in early modern Europe. Springer argues with justification that Lasco's text provided a particularly workable model for other churches to follow, especially for communities of religious refugees. Indeed, Lasco's text gave the laity in these communities a significant voice in key decisions, particularly in the selection of elders and deacons and in the reintegration of offenders into the body of the church. Yet as Springer points out, Lasco's hopes for a wider influence over the churches of his day were not met, since established churches gave a greater voice to pastors and secular leaders in church discipline and in the selection of church officers. In these established churches, lay congregations were restricted to signifying their assent to these decisions. According to Springer's analysis, Lasco had also hoped that his work would bring unity to Protestantism thanks to his emphasis on the biblical roots of the church order which he advocated. That expectation also proved to be over-optimistic. Nor was Lasco's fairly unique pattern of church leadership shared between a superintendent and Presbyterian-style representative councils replicated elsewhere in Reformed Europe, apart from Scotland (which Springer discusses) and Hungary (which he does not). In many ways, a comparison between Lasco's text and practices in Reformed Hungary and Transylvania would be helpful in assessing the relative influence of his programme. Springer's work underscores the importance of looking closely at the contributions of other Reformation leaders apart from Luther, Calvin and Zwingli. By highlighting the important contribution of religious refugees in the period, this book emphasises the significance of the refugee experience in shaping church structures and practices. Upper-level undergraduates, graduates and scholars with interests in confessional identity-building will benefit greatly from this carefully-researched and well-written book.