640 – He was native of Dalmatia, and the son of the scholasticus (advocate) Venantius. At the time of his election, he was archdeacon of the Roman Church, an important role in governing the see. As John’s consecration (on November 24) followed his election, it is supposed that the papal elections were being confirmed by the Exarch of Ravenna rather than by the Emperor in Constantinople. His exact date of birth was unknown. However, his papacy began on the 24th day of December this year.
642 – While still only pope-elect, John, with the other rulers of the Roman Church, wrote to the clergy of the North of Ireland to tell them of the mistakes they were making with regard to the time of keeping Easter, and exhorting them to be on their guard against the Pelagian heresy. About the same time he condemned Monothelism. Emperor Heraclius immediately disowned the Monothelite document known as the "Ecthesis". To Heraclius’ son, Constantine III, John addressed his apology for Pope Honorius I, in which he deprecated the attempt to connect the name of Honorius with Monothelism. Honorius, he declared, in speaking of one will in Jesus, only meant to assert that there were not two contrary wills in Him.He died of cancer on the 12th day of October this year. John was buried in the Basilica of St. Peter. He was succeded by Theodore I.