John(XX) (Nonexistent Pope. A confusion in the numbering of Popes named John after John XIV resulted because Marianus Scotus and other 11th-century historians mistakenly believed that there had been a Pope named John between antipope Boniface VII and the true John XV; XX); John(XXIII) (Schismatic antipope from 1410 to 1415; XXIII)
John(One of the most popular Popes of all times - reigned 1958-63- who inaugurated a new era in the history of the Roman Catholic Church by his openness to change, shown especially in his convoking of the second Vatican Council)
John XIX(or XX) (Pope from 1024 to 1032. Generally considered inept as Pope because of his greed, John consented to be paid for recognizing the patriarch of Constantinople; XX)
John Second Avignon Pope – reigned 1316-34 – who centralized church administration, condemned the Spiritual Franciscans, and, against Emperor Louis IV, upheld papal authority over imperial elections
John(Pope from 523 to 526 who ended the Acacian Schism - 484-519 - thus reuniting the Eastern and Western churches by restoring peace between the papacy and the Byzantine emperor Justin I)
John(Pope from 640 to 642 who perpetuated Severinus' condemnation of monothelitism. He sent an emissary to redeem Balkan Christians captured during Slavic invasions, and he defended the highly controversial orthodoxy of Pope Honorius I who had held that Christ's human and divine natures were indivisible and that the Son's will was not different from that of the Father)
John(Pope from 872 to 882. He solved a controversy over orthodoxy between the Holy See and the East by recognizing in 879 the heretofore condemned Photius as patriarch of Constantinople. Between 875 and 881 he fortified Rome against the Saracens and founded a papal navy)
John XVIII(or XIX) (Pope from 1004 to 1009. More independent of the powerful Italian Crescentii family than John XVII, he eventually abdicated and died shortly thereafter at the Abbey of St. Paul Outside the Walls, Rome; XIX)
John(Pope from 931 to about 935, the son of Marozia, dominant lady of the Roman Crescentii family. In 932/933 he was confined by his half-brother Alberic II to the Lateran and remained a prisoner until his death)
