One of Pope Adrian's first acts, after his entry into Rome, was to make Chieregati, whose learning and virtue the pope esteemed, Bishop of Teramo in the Kingdom of Naples; he then sent him to the Diet of Nuremberg, called for the autumn of 1522. He was commissioned to obtain from the German princes a more energetic pursuit of the war against the Turks in Hungary, also a more vigorous suppression of Lutheranism and the execution of the Edict of Worms against Martin Luther. In two discourses he urged the princes to co-operate for the expulsion of the Turks from Christian Hungary; on the latter date he also demanded the immediate execution of the Edict of Worms, whereby Luther had been put under the ban of the empire, which formal outlawry he had hitherto escaped through the protection of Frederick of Saxony and other friendly princes. Finally, on 3 January 1523, Chieregati read publicly two important documents, sent after him from Rome. They were a papal brief to the members of the Diet and an instruction for Chieregati himself. The former contained an appeal to the Catholic piety, religious traditions, and magnanimity of the representatives of the German people, and besought the Diet to quench religious sedition and compel the submission of Luther and his adherents. The personal instruction, issued probably on the same date, and read to the Diet by Chieregati, is one of the most important documents for the early history of the Protestant Reformation. In it Pope Adrian confesses that the sins of ecclesiastics were the chief cause of the tribulations of the Church, and that in the Roman Curia itself, both head and members, popes and prelates, had been guilty of abuses. The reply of the Diet was discouraging; the princes and representatives avoided an answer to the pope's requests, proposed the celebration of a general council in some German city, and renewed in the earlier antipapal complaints of the Germans, the famous Centum gravamina teutonicae nationis; Pastor adds that the failure of Chieregati was in large measure owing to the great German prelates who were by no means ready to repeat the confession of the pope. The latter has often been blamed for his frankness, but Pastor defends him, saying that his admissions were necessary. Chieregati was the patron of Antonio Pigafetta, who accompanied the expedition of Ferdinand Magellan. Pigafetta sent his journal of the expedition, and the voyage round the world completed by its only surviving ship, the Victoria, to Chieregati while he was at the Diet. Chieregati made it available to Diet attendees. An account of the expedition, with a globe illustrating the voyage, was also sent by Emperor Charles V to his brother Archduke Ferdinand of Austria, who was presiding at the Diet. The account was probably that taken down by Maximilianus Transylvanus, and the globe a copy of the one made by him. The globe was displayed to the attendees. Chieregati, having examined the globe, described the Victoria’s itinerary to his patron, Isabella d’Este Gonzaga, Marchesa of Mantua. Chieregati also sent Transylvanus' account to Francesco Minizio Calvo in Rome, who had it published in November 1523.
