 Meanwhile he had moved to Pavia in 1431, stimulated by his friend Panormita (Antonio Beccadelli, 1394–1471)—with whom he was soon to quarrel—and had begun to teach rhetoric. He had to flee Pavia, however, in 1433 after having aroused the anger of the jurists. In a letter to a humanist jurist friend of his, Catone Sacco (1394–1463), Valla had attacked the language of one of the lawyers’ main authorities, Bartolus of Sassoferrato (1313–1357). After some travelling, in 1435 Valla found employment at the court of Alfonso of Aragon (1396–1458), who was trying to capture Naples. Though complaining about the lack of time, books and fellow humanists, Valla was immensely productive in this phase of his career. In 1439 he finished the first version of his critique of scholastic philosophy. Two years later he finished his Elegantiae linguae Latinae, a manual for the correct use of Latin syntax and vocabulary, which became a bestseller throughout Europe. As a humanist in the court of a king who was fighting against the pope, Valla demonstrated that the Donation of Constantine, which had served the papacy to claim worldly power, was a forgery. In the same years he composed a dialogue on free will and began working on his annotations to the standard Latin translation of the Bible, comparing it with the Greek text of the New Testament. He also wrote a dialogue On the Profession of the Religious (De professione religiosorum), in which he attacked the vow of obedience and asceticism taken by members of religious orders. Further, he worked on the text of Livy, wrote a history of the deeds of Alfonso’s father, and began re-reading and annotating Quintilian’s Institutio oratoria (Education of the Orator) in a manuscript which is still extant (Paris, Bibliothèque Nationale de France, lat. 7723). But Valla’s philological approach and his penchant for quarreling made him enemies at the Aragonese court. After his patron Alfonso had made peace with the pope in 1443, Valla’s role as an anti-papal polemicist may have shrunk. His enemies took advantage of the situation. The immediate occasion was Valla’s denial of the apostolic origin of the Symbolum Apostolicum (Apostle’s Creed). In a letter, now lost, to the Neapolitan lawyers he argued that a passage from Gratian’s Decretum that formed the basis of the belief in the apostolic origin of the Creed was corrupt and needed emendation. Powerful men at the court staged an inquisitorial trial to determine whether Valla’s works contained heretical and heterodox opinions. In preparation for the trial Valla wrote a self-defense (and later an “Apology”), but was rescued from this perilous situation by the intervention of the king. The whole affair must have fuelled Valla’s wish to return to Rome. In 1447 he made peace with the pope and became an apostolic scriptor (scribe), and later, in 1455, a papal secretary. In these years he revised some of his earlier works such as the Repastinatio and his notes on the New Testament, and translated Thucydides and Herodotus into Latin; his work on Thucydides, in particular, was to have an important impact on the study of this difficult Greek author. Always an irascible man, he continued to engage in quarrels and exchanged a series of invectives with his arch-enemy Poggio. He died in 1457, still working on a second revision of his Dialectics (that is, the third version). He was buried in the Lateran, where his grave was removed in the sixteenth century, probably between the 1560s and 1580s at a time when his works were put on the Index; the present memorial is not Valla’s tombstone.