Pope John IV (died 12 October 642) was elected Pope of the Catholic Church, after a four-month sede vacante, on 24 December 640.

Pope John was a native of Dalmatia (probably in the town of Salona). He was 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 24 December 640 followed very soon after his election, and it is supposed that the papal elections were being confirmed by the Exarch of Ravenna rather than by the Emperor in Constantinople.

Troubles in his native land caused by invasions of Slavs directed John's attention there. To alleviate the distress of the inhabitants, John sent the abbot Martin into Dalmatia and Istria with large sums of money for the redemption of captives. As the ruined churches could not be rebuilt, the relics of some of the more important Dalmatian saints were brought to Rome. John erected an oratory in their honour which still stands. It was adorned by the pope with mosaics depicting John himself holding in his hands a model of his oratory. John endeavoured thereby to convert the Slavs in Dalmatia and Istria to Christianity. Emperor Constantine Porphyrogenitus claimed that Porga, duke of the Dalmatian Croats, who had been invited into Dalmatia by Heraclius, sent to Emperor Heraclius for Christian teachers. It is supposed that the Emperor to whom this message was sent was Emperor Heraclius himself, and that he sent it to Pope John IV.

John IV may refer to:

Pope Saint John I (c. 470 – 18 May 526) was Pope from 523 to 526. He was a native of Siena (or the "Castello di Serena"), near Chiusdino. He is the first pope known to have visited Constantinople while in office.

While a deacon in Rome, he is known to have been a partisan of the Antipope Laurentius, for in a libellus written to Pope Symmachus in 506, John confessed his error in opposing him, anathematized Peter of Altinum and Laurentius, and begged pardon of Symmachus. He would then be the deacon John who signed the acta of the Roman synod of 499 and 502; the fact the Roman church only had seven deacons at the time makes identifying him with this person very likely. He may also be the deacon John to whom Boethius dedicated three of his five religious tractates written between 512 and 520.

John was very frail when he was elected to the papacy. Despite his protests, he was sent by the Arian King Theodoric the Great of the Ostrogoths to Constantinople to secure a moderation of Emperor Justin's decree of 523 against the Arians. Theodoric threatened that if John should fail in his mission, there would be reprisals against the orthodox Catholics in the West. John proceeded to Constantinople with a considerable entourage: his religious companions included bishop Ecclesius of Ravenna, bishop Eusebius of Fanum Fortunae, and Sabinus of Campania. His secular companions were the senators Flavius Theodorus, Inportunus, Agapitus, and the patrician Agapitus.

Pope John Paul I (Latin: Ioannes Paulus PP. I, Italian: Giovanni Paolo I), born Albino Luciani (17 October 1912 – 28 September 1978), reigned as Pope of the Catholic Church and as Sovereign of Vatican City from 26 August 1978 until his death 33 days later. His reign is among the shortest in papal history, resulting in the most recent Year of Three Popes. John Paul I was the first Pope to be born in the 20th century and the last Pope to die in it.

In Italy he is remembered with the appellatives of "Il Papa del Sorriso" (The Smiling Pope) and "Il Sorriso di Dio" (The smile of God).Time magazine and other publications referred to him as The September Pope.

Albino Luciani was born on October 17, 1912 in Forno di Canale (now Canale d'Agordo) in Belluno, a province of the Veneto region in Northern Italy. He was the son of Giovanni Luciani (1872?–1952), a bricklayer, and Bortola Tancon (1879?–1948). Albino was followed by two brothers, Federico (1915–1916) and Edoardo (1917–2008), and a sister, Antonia (1920–2009).

Paul VI (Latin: Paulus PP. VI; Italian: Paolo VI), born Giovanni Battista Enrico Antonio Maria Montini (26 September 1897 – 6 August 1978), reigned as Pope of the Catholic Church from 21 June 1963 until his death on 6 August 1978. Succeeding Pope John XXIII, who had convened the Second Vatican Council, he decided to continue it. He fostered improved ecumenical relations with Orthodox and Protestants, which resulted in many historic meetings and agreements.

Montini served in the Vatican's Secretariat of State from 1922 to 1954. While in the Secretariat of State, Montini and Domenico Tardini were considered as the closest and most influential co-workers of Pope Pius XII, who named him in 1954 Archbishop of Milan, the largest Italian diocese, yet denying him the Cardinal designation that traditionally accompanies being Archbishop of Milan, a function which made him automatically Secretary of the Italian Bishops Conference. John XXIII elevated him to the College of Cardinals in 1958, and after the death of John XXIII, Montini was considered one of his most likely successors.