ANTONIO CARDINAL BARBERINI, iuniore (1607-1671), was the son of Carlo Barberini and Costanza Magalotti. He was the nephew of Pope Urban VIII (Maffeo Barberini, 1623-1644), of the Capuchin Antonio Card. Barberini, seniore, (1624), and of Lorenzo Card. Magalotti. His brother Francesco became Cardinal on the election of their uncle to the papacy, and his brother Taddeo became Prince of Palestrina and Prefect of Rome. He was the cousin of Francesco Maria Card. Machiavelli (who became cardinal in 1641), and uncle of Carlo Cardinal Barberini (1653). He was Grand Prior in Rome of the Order of St. John of Jerusalem.

The accession of his uncle brought Antonio Barberini and his brothers many positions of power, wealth and influence. He became Cardinal Deacon of S. Maria in Aquiro in 1627, and Camerlengo of the Holy Roman Church on July 28, 1638, a position which he held until his death on August 3, 1671. In that capacity he presided over the Conclaves of 1644, 1655, 1667 and 1669-1670. The authoritarianism, arrogance and greed of the family ("Quod non fecerunt Barbari, fecerunt Barberini.") brought a strong reaction on the death of Urban VIII. In 1645 Antonio and Taddeo fled to Paris (where Urban VIII had once been ambassador), and remained in exile at the Court of Louis XIV (under the patronage of the Sicilian Giulio Card. Mazzarini) until 1653; he became Grand Almoner of France and a member of the Order of the Holy Spirit. In 1657 he was nominated Archbishop of Rheims, a choice which was approved by Pope Alexander VII. He became Cardinal Bishop of Palestrina in 1661. He died in Rome on August 3, 1671.

Cardinal Barberini was Cardinal Camerlengo during the conclaves of 1644, 1655, 1667 and 1670.

Pope Innocent X (Pamphilj) died on January 7, 1655. He had been ill since August (Novaes, pp. 53-55), and his expected death caused most people of consequence to be gathered in Rome, including most of the cardinals. During the last year of the pope's life, his sister-in-law Olimpia Maidalchini scarcely ever left his side, completely controlling access to the Pope and to the money she could make and power she could wield through him. In the last weeks of his life, it was said, she would lock him in his room once a week while she removed money and other valuables from the Papal Palace to her own palace. Even with his death she did not flee the inevitable retribution, believing that she could produce a friendly result in the conclave through the exercise of influence and money. She had many to fear, foremost among them Giovanni Battista Cardinal Pallotta, the Dominican Cardinal Vincenzo Maculani, and Domenico Cardinal Cecchini. Her chosen agent is said to have been Cardinal Barberini, though she worked through a number of people, appointees of Innocent X, who came to be called her Flying Squadron (Squadron Volante). Cardinal Pallavicini names them (Ranke, p. 36n.): Cardinals Lorenzo Imperiale, Luigi Omodei, Giberto Borromeo, Benedetto Odescalchi, Carlo Pio di Savoia, Aquaviva, Pietro Ottoboni, Francesco Albizzi, Carlo Gualtiero, and Decio Azzolino. The dead pope she left to his own fate, not even providing him a proper coffin for his lying-in-state.

The Conclave of 1655 lasted eighty days. It began on January 18, the Feast of the Chair of St. Peter in Rome, with the Mass of the Holy Spirit. Sixty-two cardinals entered conclave on that day; four others arrived by the 7th of February. Pier Luigi Cardinal Carafa died during the conclave, on February 15. Amazingly, only three cardinals were not present, including Jules Cardinal Mazarin, the French First Minister.

Fourty-four votes were needed to elect. According to Pallavicino, there were four factions. One, the larrgest, was led by Cardinal Barberini, the Camerlengo; the cardinals created by his uncle, Urban VIII, mostly adhered to his group. The Spanish interest was led by Carlo Cardinal de' Medici, the uncle of Grand Duke Ferdinand II (1621-1670), and Dean of the Sacred College. The small French faction was led by Rinaldo Cardinal d'Este, the brother of the Duke of Modena (who was feuding with the Camerlengo).. In the fourth group were the cardinals created by the deceased pope Innocent (He had created forty cardinals in all; only six had died by the opening of the conclave). These last were inclined to support Fabio Cardinal Chigi, the Secretary of State of Innocent X, who had been the principal papal negotiator at the Peace of Westphalia (in Münster) in 1648. Ironically, Chigi's successes at bringing about a peace had been contrary to the designs of Cardinal Mazarin, and he was thus unfriendly to Chigi's candidacy. But they were supported by the Spanish Ambassador in Rome.

Though Giulio Cesare Cardinal Sacchetti had been vetoed (the esclusiva) by the Spanish Government in the Conclave of 1644, he was still, at the age oif 68, a person of interest (soggeto) in 1655. Barberini commanded about 18-20 votes at the beginning, Chigi about 18 likewise (Novaes, p. 71). Francesco Cardinal Rappacioli (Bishop of Terni) was a soggetto, but he was young, sickly, and opposed by the French interest (Cardinal Spada carried an exculsiva against him—which in the event was never used).

Finally, Cardinal Sacchetti wrote to Mazarin, who was induced to withdraw the threat of a French Veto against Chigi. On the sixth of April, the two Cardinals Barberini, the two cardinals de' Medici, and Cardinal d' Este called on Chigi, and informed him that they had finally come to an understanding and that they intended to elect him pope. Their visit was followed by many others. On the seventh of April, Fabio Cardinal Chigi, Cardinal Priest of S. Maria del Popolo, Bishop of Imola, was elected unanimously. He was crowned Pope Alexander VII on Sunday, April 18, by the Cardinal Protodeacon, Giangiacomo Cardinal Trivulzi, and on May 9 he took formal possession of S. Giovanni Laterano.

For the Conclave of 1655, see: Antonio Bagata, "Life of Alexander VII," in Storia delle vite de' pontefice di Bartolommeo Platina e d' altri autori . . fino a Clemente XIII . . . Tomo IV (Venezia Domenico Ferrarin 1765), pp. 371-382, at 373-375; J. Valfrey, Hughes de Lionne, ses ambassades en Italie, 1642-1656, d' après son correspondence (Paris 1877) 194-248. Giuseppe de Novaes, Elementi della storia de' sommi pontefici da San Pietro sino al ... Pio Papa VII   third edition, Volume 10 (Roma 1822) 69-74. Gaetano Moroni Dizionario di erudizione storico-ecclesiastica Volume 1 (Venezia 1841) 243; and F. Artaud de Montor, Histoire des souverains pontifes Romains Tome VI (Paris 1851) 18-20 (both leave the details in darkest silence). John Bargrave, Pope Alexander the Seventh and the College of Cardinals [1672] (Camden Society 1867) gives sketches of each cardinal and their affiliations. T. A. Trollope, The Papal Conclaves, as they were and as they are (London 1876), 330-335, and, in a visibly protestant vein, A Decade of Italian Women Volume II (London 1859) 358-363. A salacious, outrageous, and occasionally untrustworthy account is given by an alleged eyewitness, Gregorio Leti, writing as "Reverend Gualdus", in Biography of Donna Olimpia Maidalchini by the Abbe Gualdi (Philadelphia 1846) 68-73. Leopold von Ranke, History of the Popes, their Church and State (translated by E. Fowler) revised edition, Volume III (New York: The Colonial Press 1901), 34-37.