Georgius Cassander (1513–66) was a humanist scholar who lived and worked in the northern Rhineland, between Bruges and Cologne. He is best known for his irenic works on inter-confessional relations between Protestants and Catholics, where he sought to resolve ‘the complex theological and religious-political issues that pre-occupied people's minds’ (p. 3) by publishing editions of Church Fathers, prayers, hymns and philology. Invited to attend the Colloquy of Poissy in France in 1561 by a monarchy beset with religious tensions, he declined on health grounds but instead produced a document outlining his ideas for achieving religious peace. This was published in Basel in August 1561 as De officio pii viri. In this, Cassander asserted that whoever subscribed to the essence of Christian doctrine, regarded Scripture as the basis for the Christian faith and accepted Christ as his Redeemer, was true to the head of the Church. It was received with hostility by John Calvin and others but it had a certain longevity of impact, for it continued to be issued and debated over the following century. Rob Van de Schoor, working in part with materials prepared by the late Posthumus Meyjes, has produced a critical edition of the 1561 publication of De officio pii viri along with scholarly apparatus for the text. There is a useful, short introduction to Cassander's life and works, with a discussion of the subsequent publication history of the text and a list of extant versions. Van de Schoor's edition is informed methodologically by the ‘new philology’ of examining all extant texts of a work, in their different contexts. Van de Schoor also provides a contemporary German translation (the 1562 edition of Georg von Cell) and a French translation by Jean Hotman, the three texts produced in very useful parallel form. These are accompanied by an English translation by the editor. The editions of De officio pii viri are supported by a range of other contemporary documents under the heading of ‘The afterlife of De officio pii viri’. These were products of the polemical disputes which followed Poissy, first by Calvin then by a range of Reformed and Catholic authors. There is a detailed examination of the French editions of Jean Hotman and François Bauduin, the earliest and most important editions, and of the Prussian editions of Johann Latermann and Abraham Calovius. In sum, the whole book is a well-produced and valuable source for advanced students and researchers working on the Reformations; it includes detailed footnotes and a bibliography.