the Papal States, his niece's son, Cardinal Raffaele Riario (for whom the Palazzo della Cancelleria was constructed) was suspected of colluding in the failed Pazzi conspiracy of 1478 to assassinate both Lorenzo de' Medici and his brother Giuliano and replace them in Florence with Sixtus IV's other nephew, Girolamo Riario. Francesco Salviati, Archbishop of Pisa and a main organizer of the plot, was hanged on the walls of the Florentine Palazzo della Signoria. Sixtus IV replied with an interdict and two years of war with Florence. However, Infessura had partisan allegiances to the Colonna and so is not considered to be always reliable or impartial. The English churchman and Protestant polemicist John Bale, writing a century later, attributed to Sixtus "the authorisation to practice sodomy during periods of warm weather" to the "Cardinal of Santa Lucia". This prompted the noted historian of the Catholic Church, Ludwig von Pastor, to issue a firm rebuttal. Foreign policy Sixtus continued a dispute with King Louis XI of France, who upheld the Pragmatic Sanction of Bourges (1438), which held that papal decrees needed royal assent before they could be promulgated in France. That was a cornerstone of the privileges claimed for the Gallican Church and could never be shifted as long as Louis XI manoeuvred to replace King Ferdinand I of Naples with a French prince. Louis was thus in conflict with the papacy, and Sixtus could not permit it. On 1 November 1478, Sixtus published the papal bull Exigit Sincerae Devotionis Affectus through which the Spanish Inquisition was established in the Kingdom of Castile. Sixtus consented under political pressure from Ferdinand of Aragon, who threatened to withhold military support from his kingdom of Sicily. Nevertheless, Sixtus IV quarrelled over protocol and prerogatives of jurisdiction; he was unhappy with the excesses of the Inquisition and condemned the most flagrant abuses in 1482. As a temporal prince who constructed stout fortresses in the Papal States, he encouraged the Venetians to attack Ferrara, which he wished to obtain for another nephew. Ercole I d'Este, Duke of Ferrara, was allied with the Sforzas of Milan, the Medicis of Florence along with the King of Naples, normally a hereditary ally and champion of the papacy. The angered Italian princes allied to force Sixtus IV to make peace to his great annoyance. For refusing to desist from the very hostilities that he himself had instigated and for being a