Geheimprotestantismus und evangelische Kirchen is a timely volume of edited essays examining the phenomenon of crypto-Protestantism in the Habsburg lands and Salzburg archbishopric in the seventeenth and eighteenth centuries. Many forget that at one juncture in the sixteenth century Vienna was a predominately Protestant city. Indeed, it is hard to imagine that during this period an imperial court preacher actually referred to Catholic clergy as ‘miserable leaders of the blind and hangmen of souls’. The volume under review considers the Protestant communities of this region not during the Reformation but during the high point of both Austrian absolutism and Catholic Reformation. The editors have divided the collection into three main sections. An introductory division of three major essays lays out the general contours of the project and provides a broad overview of the period and region. Martin Scheutz discusses the usefulness of the confessionalisation paradigm for the Habsburg lands while Karl Schwarz offers a helpful survey of the legal status of Protestantism from the 1555 settlement of Augsburg to the 1648 Peace of Westphalia. At the heart of the volume are nine essays examining Geheimprotestantismus in the various regions of the Habsburg lands as well as the archdiocese of Salzburg. Apart from Austria proper, attention is also given to Bohemia, Silesia and Hungary. Silesia and Hungary are particularly interesting points of comparisons as Protestantism here had a degree of legal protection. A final group of essays highlights common themes. Forced emigration, conversion, Catholic mission work and connections with Protestants of the Reich are among the issues investigated. Originally conceived as a Handbuch or reference guide, this is a useful and coherent collection of essays that should become the starting point for any future research on crypto-Protestantism in the Habsburg lands during the seventeenth and eighteenth centuries.