"This is a well informed book, with some innovative observations and offering a healthily critical stance free of methodological and ideological prejudices. It will become a companion for anyone interested in issues such as Priscillianism, the primacy of Rome in the western Church in Late Antiquity, and the importance of the Church in the construction of the Suevic and Gothic kingdoms in Spain in this period." Luis A. García Moreno, Real Academia de la Historia, Spain "This is a detailed and independent-minded study of the various theological issues discussed in the surviving papal letters that were sent to recipients in the Iberian Peninsula between the third and seventh centuries. It pays particular attention to the use in them of claims of Petrine primacy and how these developed over the course of this period. In stressing the way in which the popes consistently combined the assertion of their own unique apostolic responsibility with reference to other sources of authority, notably ecumenical councils, this book illuminates the key episodes in the history of relations between the Spanish church and the Papacy in these centuries." Roger Collins, Honorary Fellow School of History, Classics and Archaeology, University of Edinburgh, UK.