This volume has a misleading combination of title and subtitle. If, as is conventional, the reader takes the latter to qualify the former, then we have a very short study indeed, for the tentative and fruitless attempts of the Catholic bishop Rojas y Spinola in 1691–2 to interest a few Hungarian Protestants in the reunion of the universal Church occupy a mere ten pages of Forgó's text and yield no significant new insights. Rather we need to see the book as covering both subject areas equally. As such it provides a helpful survey, building on the existing literature, of ecumenical initiatives in Hungary during the whole period, and of Rojas's own activities in the same cause elsewhere in central Europe. The utility of the work thus consists in suggesting wider linkages and parallels between two separate Catholic programmes: on the one hand, the overtures largely to Orthodox communities in Hungary; and on the other, the negotiations largely with German Protestants that began in the circle around Johann Christian von Boineburg at Mainz in the 1650s and later spread to other parts of the Reich. But whereas the Hungarian enterprise yielded new Uniate churches which have survived to our own day, Rojas never had much to show for his labours. For all the sincerity of this indefatigable and persuasive prelate, many saw his work as an evident stratagem to encourage conversion; and besides, he never had a clear mandate from Rome to offer concessions to the other side. This book too is rather a missed opportunity. It could have broken new ground by examining some of the practical forms of religious accommodation reached in Hungary at that time, such as are suggested by the cover picture of a village church which served as a simultaneum, a building used in parallel by Catholics, Lutherans and Calvinists.