This study discusses hitherto unknown aspects concerning the papal censure of the work by the Spanish jurist Juan de Solórzano Pereira, author of the two-volume treatise on Derecho indiano, known as the Disputationes de Indiarum Iure. Immediately after the publication of its second part in 1639, the Curia (under the government of Pope Urban VIII Barberini) prompted the Congregation of the Index in Rome to examine Solórzano's seminal treatise and, eventually, condemn its section about Spain's royal patronage of the Church. By looking at the circumstances of the censure (e.g. the early ‘leak’ orchestrated by the Congregation, the other reports about the censure), the present work aims at bringing to the attention of scholars the Solórzano file conserved in the Vatican archives. Considering both the reasons of the censure and the circumstances under which it developed, the present study sheds new light on the complex relationship between Spain and the Papacy in the first half of the seventeenth century and beyond. [ABSTRACT FROM AUTHOR]