16. Constantine was the Greek emperor after John Palaeologus. When he sent ambassadors to Nicholas V to beseech help for his faltering fortunes, he was careful to profess that he would make every effort to implement as fully as could be desired the harmony which was agreed on at Florence, and that consequently he would see to it that the name of the Roman pontiff was restored to the sacred diptychs. This is attested by Ducas in his Historia Byzantina: The emperor had already sent to Rome to request reinforcements with the additional purpose of strengthening the harmony achieved at Florence and of having the Pope's name proclaimed from the sacred diptychs during the liturgies of the great church." The Pope showed himself ready to give him as much aid as he could and continued at the same time to exhort him to promulgate the decree of the union which had been agreed on at the Council of Florence. He urged him to see to it that the name of the Roman pontiff "was proclaimed in the diptychs and that the whole Greek church prayed for him expressly and by name, as was the former practice of men who were pleasing to God, both patriarchs of Constantinople and emperors" (Raynaldus, Annales, 1451 A.D., no. 2).