Tridentini refutata. In addition to these sources Pallavicino continued searching the vast holdings of the roman archives for documentary materials relating to the Council of Trent. Fabio Chigi, an old friend of Pallavicino, gave him liberal access to the acts of the council and other important documents preserved in the Vatican Apostolic Archive. Pallavicino read and made use of historical authors such as Johannes Sleidanus, Francesco Guicciardini, Paolo Giovio, Nicholas Sanders, François de Beaucaire (1514–1591), and Florimond de Raemond. Thanks to the preparatory work by Alciati, as well as his own research, he was able to cite a large array of printed and unpublished documentary sources on the Council of Trent. Pallavicino's History exposed Sarpi's bias and inaccuracy and marked an advance in the collection and use of original documents. According to the great nineteenth-century historian Leopold von Ranke, who examined many of the manuscript sources from which Pallavicino drew his materials, the extracts he has made from the instructions and other official documents are “scrupulously exact” and he has “carefully consulted the whole of the documents”. Until the twentieth century, Pallavicino's History of the Council of Trent was the principal work on this important ecclesiastical assembly. It was appreciated even by Protestant scholars: Algernon Sidney, who knew Pallavicino at Rome, commends the work in a letter to his father, Lord Leicester. Pallavicino's History was translated into Latin by a fellow Jesuit, Giovanni Battista Giattini (Antwerp, 1670–1673), into French by Joseph-Epiphane Darras (Migne series, Paris, 1844–1845); into Spanish by Juan Nepomuceno Lobo, Antolín Monescillo, and Manuel M. Negueruela (Madrid, 1846) and into German by Theodor Friedrich Klitsche de la Grange (1835–1837). There is a good edition of the original by Francesco Antonio Zaccaria (6 vols., Faenza, 1792–1799). The codex used by Francesco Sforza Pallavicino to write his Istoria is preserved in the Archives of the Pontifical Gregorian University (APUG). Original publication Other works Literary works Before his entrance into the Jesuit order Pallavicino had published orations and poems. His great poem I fasti sacri, an imitation of Ovid's Fasti celebrating the main Christian feast days, was left unfinished upon his entrance into the novitiate. Pallavicino's Fasti were praised by Ludovico Antonio Muratori Giovanni Mario Crescimbeni, and Francesco Saverio Quadrio. His first considerable literary work as Jesuit was a tragedy, Ermenegildo martire, a masterpiece of seventeenth-century Jesuit drama. It was published in 1644 after the first of several performances at the