Born at Rome, 6 May, 1574; died there, 7 January, 1655. His parents were Camillo Pamfili and Flaminia de Bubalis. The Pamfili resided originally at Gubbio, in Umbria, but came to Rome during the pontificate of Innocent VIII. The young man studied jurisprudence at the Collegio Romano and graduated as bachelor of laws at the age of twenty. Soon afterwards Clement VIII appointed him consistorial advocate and auditor of the Rota. Gregory XV made him nuncio at Naples. Urban VIII sent him as datary with the cardinal legate, Francesco Barberini, to France and Spain, then appointed him titular Latin Patriarch of Antioch, and nuncio at Madrid. He was created Cardinal-Priest of Sant' Eusebio on 30 August, 1626, though he did not assume the purple until 19 November, 1629. He was a member of the congregations of the Council of Trent, the Inquisition, and Jurisdiction and Immunity. On 9 August, 1644, a conclave was held at Rome for the election of a successor to Urban VIII. The conclave was a stormy one. The French faction had agreed to give their vote to no candidate who was friendly towards Spain. Cardinal Firenzola, the Spanish candidate was, therefore, rejected, being a known enemy of Cardinal Mazarin, prime minister of France. Fearing the election of an avowed enemy of France, the French party finally agreed with the Spanish party upon Pamfili, although his sympathy for Spain was well known. On 15 September he was elected, and ascended the papal throne as Innocent X.
Soon after his accession, Innocent found it necessary to take legal action against the Barberini for misappropriation of public moneys. To escape punishment Antonio and Francesco Barberini fled to Paris, where they found a powerful protector in Mazarin. Innocent confiscated their property, and on 19 February, 1646, issued a Bull ordaining that all cardinals who had left or should leave the Ecclesiastical States without papal permission and should not return within six months, should be deprived of their ecclesiastical benefices and eventually of the cardinalate itself. The French Parliament declared the papal ordinances null and void, but the pope did not yield until Mazarin prepared to send troops to Italy to invade the Ecclesiastical States. Henceforth the papal policy towards France became more friendly, and somewhat later the Barberini were rehabilitated. But when in 1652 Cardinal Retz was arrested by Mazarin, Innocent solemnly protested against this act of violence committed against a cardinal, and protected Retz after his escape in 1654. In Italy Innocent had occasion to assert his authority as suzerain over Duke Ranuccio II of Parma who refused to redeem the bonds (monti) of the Farnesi from the Roman creditors, as had been stipulated in the Treaty of Venice on 31 March, 1644. The duke, moreover, refused to recognize Cristoforo Guarda, whom the pope had appointed Bishop of Castro. When, therefore, the new bishop was murdered while on his way to take possession of his see, Innocent held Ranuccio responsible for the crime. The pope took possession of Castro, razed it to the ground and transferred the episcopal see to Acquapendente. The duke was forced to resign the administration of his district to the pope, who undertook to satisfy the creditors. The papal relations with Venice, which had been highly strained during the pontificate of Urban VIII, became very friendly during Innocent's reign. Innocent aided the Venetians financially against the Turks in the struggle for Candia, while the Venetians on their part allowed Innocent free scope in filling the vacant episcopal sees in their territory, a right which they had previously claimed for themselves. In Portugal the popular insurrection of 1640 had led to the secession of that country from Spain, and to the election of Juan IV of Braganza as King of Portugal. Both Urban VIII and Innocent X, in deference to Spain, refused to acknowledge the new king and withheld their approbation from the bishops nominated by him. Thus it happened that towards the end of Innocent's pontificate there was only one bishop in the whole of Portugal. On 26 November, 1648, Innocent issued the famous Bull "Zelo domus Dei", in which he declares as null and void those articles of the Peace of Westphalia which were detrimental to the Catholic religion. In his Bull "Cum occasione", issued on 31 May, 1653. he condemned five propositions taken from the "Augustinus" of Jansenius, thus giving the impulse to the great Jansenist controversy in France.
Innocent X was a lover of justice and his life was blameless; he was, however, often irresolute and suspicious. The great blemish in his pontificate was his dependence on Donna Olimpia Maidalchini, the wife of his deceased brother. For a short time her influence had to yield to that of the youthful Camillo Astalli, a distant relative of the pope, whom Innocent raised to the cardinalate. But the pope seemed to be unable to get along without her, and at her instance Astalli was deprived of the purple and removed from the Vatican. The accusation, made by Gualdus (Leti) in his "Vita di Donna Olimpia Maidalchini" (1666), that Innocent's relation to her was immoral, has been rejected as slanderous by all reputable historians.
CIAMPI, Innocenzo X Pamfili e la sua corte (Imola, 1878); FRIEDENSBURG, Regesten zur deutschen Geschichte aus der Zeit des Pontifikats Innocenz X in Quellen und Forschungen, edited by the Prussian Historical Institute in Rome, V (1902), VI (1903); RANKE, Die römischen Päpste, tr. FOSTER, II (London, 1906), 321-9; BAROZZI E BERCHET, Relazioni degli stati Europei lette al senato dagli Ambasciatori Veneti nel secolo decimosettimo, Serie III: Italia, Relazioni di Roma, II (Venice, 1878), 43-161; PALATIUS, Gesta Pontificum Romanorum, IV (Venice. 1688), 571-94.