The emperor, Nicephorus, after winning many notable victories in Moesia, fell in battle against the Bulgarians, and his son-in-law Michael was made emperor. He received the ambassadors in Constantinople whom Karl had sent to Nicephorus and dismissed them, sending back to Karl with them his own ambassadors, Michael, a bishop, and Arsaphius and Theognostus, commanders of the imperial body-guard, to confirm the treaty which had been proposed in the time of Nicephorus. They came to the emperor at Aachen and received a copy of the treaty from him in the church of Aachen. In their address to him on this occasion, which they delivered in Greek, they called him emperor and _basileus_. They then proceeded to Rome on their way back, and received a copy of the treaty from the pope in the church of St. Peter, the apostle. 14. Letter of Karl to Emperor Michael I, 813. Jaffé, IV, pp. 415 f. In the name of the Father, Son, and Holy Spirit. Karl, by the grace of God emperor and Augustus, king of the Franks and the Lombards, to his dear and honorable brother, Michael, glorious emperor and Augustus, eternal greeting in our Lord Jesus Christ. We bless and praise our Lord Jesus Christ with all our heart and strength for the ineffable gift of his kindness, with which he has enriched us. For he has deigned in our day to establish that peace between the east and the west, which we have long sought for and have always desired, and, in answer to the daily prayers which we have offered to him, has unified the holy immaculate catholic church throughout the whole world and given it peace. We speak of this peace as if it had been already brought about, for we have done our part, and we are sure you are willing to do yours. We put our trust in God who has ordained that this matter, the making of peace between us, should be carried out; for he is faithful and true, giving his aid to all who are engaged in good works, and he will bring to perfection this work which we have begun. Desiring now to bring about this consummation, we have sent you our legates, Amalhar, venerable bishop of Trier, and Peter, abbot of the monastery of Nonantula, to receive from the holy altar by your hands a copy of the treaty of peace, bearing the signatures of your priests, patriarchs, and nobles, just as your legates, Michael, venerable metropolitan, and Arsaphius and Theognostus, commanders of the royal body-guard, received the copy from us, with our signature and the signatures of our priests and nobles.... 15. Letter to Ludwig the Pious Concerning the Appearance of a Comet, 837. Jaffé, IV, pp. 459 f.