John V's papacy saw a continuation of improving relations with Byzantium. The Emperor greatly reduced taxes on the papal patrimonies of Sicily and Calabria and abolished other taxes, such as a surtax on grain that had been paid only with difficulty in recent years. A letter from Justinian II assured John V that a "synod of high-ranking civil and ecclesiastical officials", including the "apocrisiarius" and the Byzantine military, had read and thereafter sealed the text of the Third Council of Constantinople, to prevent any alteration to its canons. The letter was addressed to "John pope of the city of Rome", written while the Emperor believed the pope to still be alive, but received by Pope Conon.