Description: This is the first English translation of one of the most important treatises written during the late-Middle Ages in defense of converts from Judaism, favoring religious tolerance in the face of religious and racially motivated prejudice and violence. The book also includes a fresh Latin edition, drawing on all known manuscripts. The text was written in response to the actions of the "Old Christians" of Toledo against the "New Christians," also called conversos, in 1449. A letter of Pope Nicholas V favouring the converts is included.
Brief description:
Thomas M. Izbicki, Ph.D. (Cornell University, 1973), is a humanities librarian emeritus at Rutgers University. He is a researcher in the fields of medieval canon law, the history of the papacy, and the history of the Order of Preachers. He has published Protector of the Faith: Cardinal Johannes de Turrecremata and the Defense of the Institutional Church (1981) and The Eucharist in Medieval Canon Law (2015).
Jorge Ledo, Ph.D. (University of Aberdeen, 2009), is a 'Ramón y Cajal' Researcher at the Universidade da Coruña (Spain). He is an intellectual historian specialized in Renaissance Humanism and in the history of religious minorities and religious dissidence in early-modern Spain. He has published Moria de Erasmo Roterodamo. A Critical Edition of the Early Modern Spanish Translation of Erasmus's Encomium Moriae (2014).
Review Quotes: "This edition of the Tractate against the Midianites and Ishmaelites will be immensely useful to scholars of fifteenth-century Iberia, intellectual and religious history, as well as those exploring questions of premodern race and racialization. The format and critical apparatus mean that the text--written by one of the most important Curia theologians of the mid-fifteenth century--could also serve as a good introduction to late medieval Latin and theology for advanced students. Overall, it is a welcome addition to Brill's Heterodoxia Iberica series." -- Bert Carlstrom, Queen Mary University of London
"Thanks are due to Thomas Izbicki and Jorge Ledo for making available a very important text in its first English translation, based on three different manuscripts." -- Michaela Valente, Sapienza Università di Roma, in Renaissance Quarterly 79.2 (Summer 2026)