Papal election, 1241
The papal election, following the death of Pope Gregory IX, from September 21 to October 25, 1241 elected Cardinal Goffredo da Castiglione as Pope Celestine IV. The election took place during the first of many protracted sede vacantes of the Middle Ages, and like many of them was characterized by disputes between popes and the Holy Roman Emperor. Specifically, the election took place during the war between Frederick II, Holy Roman Emperor against the Lombard League and the deceased pontiff, Pope Gregory IX, with Italy divided between pro-Papal and pro-Imperial factions known as the Guelphs and Ghibellines.
During the sede vacante, Frederick II surrounded Rome with his armies, blocking the arrival of some cardinal electors known to be hostile to his interests. Unable to reach a consensus, the cardinals were locked in a monastery called the Septasolium (corrupted in both medieval and modern narratives into Septizodium) by the Roman civic officials, eventually settling on one of their oldest and most feeble members. The conditions within the building were believed to have contributed to the death of one of the papabile and even to the death of Celestine IV soon after the election. Following Celestine IV's death, the war on the peninsula resumed and the cardinals dispersed for over a year and a half before coming together in Anagni to elect Pope Innocent IV.
The forced sequestration of the cardinals during the election was historically significant, and—along with other papal elections of the 13th century—contributed to the development of the papal conclave.
The papacy of Pope Gregory IX (1227–1241) and the kingship of Frederick II, Holy Roman Emperor took place at a time when centuries-old disputes between the popes and emperors were coming to a head. Frederick II had dedicated troops, but not his own leadership, to the failed Fifth Crusade, to the dismay of the church; following his marriage to Yolande of Jerusalem, he took up the Sixth Crusade but later abandoned it and returned to Italy, for a variety of political, economic, and military reasons. This served as a pretext for his excommunication by Gregory IX, and thinly veiled skirmishes between supporters of the pope and emperor (Guelphs and Ghibellines, respectively) throughout the Italian peninsula, particularly in Lombardy. Before his death, Gregory IX had called for a synod to denounce Frederick II, and the emperor had gone to great lengths to disrupt the gathering, including the imprisonment of captured prelates and cardinals.
The conclave took place under the threat of the surrounding army of Frederick II, Holy Roman Emperor (before he pulled back to Apulia: Frederick II's retreat was meant to show that the Emperor "had made war with Gregory IX, and not with the Church".), who had been at odds with Gregory IX and then Celestine IV. Two cardinals had been sent to England (Oddo de Monferrato) and France (Giacomo da Pecorara, OCist.), in order to rally bishops and other prelates to attend Pope Gregory's Council. Since Frederick and his army held the Lombard plain and Tuscany, travelers would have to take the sea route. A navy was assembled by the two cardinals at Nice and Genoa, and despite warnings from the Genoese, they insisted on setting sail. They were met by Frederick's fleet off the tiny island of Giglio on 3 May 1241, and large numbers of the travelers, including the two cardinals, the papal Legate for Lombardy, and the Archbishops of Rouen, Bordeaux, and Auxerre; the Bishops of Nîmes, Carcassone, Agde, Pavia, Asti, and Tortona; the Abbots of Cluny, Citeaux, Clairvaux, Pietas-Dei and Fiscanensis. They were sent to imprisonment in the Kingdom of Naples. The election took place in the Saepta Solis ('enclosure of the Sun') near the Clivus Scauri, an ancient complex that had been turned into a monastery. The cardinals were confined by Senator Matteo Rosso Orsini, the father of Giovanni Caetano Orsini (Pope Nicholas III), who had been appointed to his office by Pope Gregory IX. The conditions of the election were reported — by a contemporary author hostile to the Orsini — to have been stressful, with the urine of Orsini's guards on the rooftop leaking into the election chamber along with the rain. The actual forced confinement to the Saepta Solis took place only for the last two weeks of the conclave. It is even alleged that the citizens of Rome, angered by rumors that a non-Cardinal would be elected, threatened to dig up the corpse of Pope Gregory IX and place it in the Saepta Solis with the cardinals. A different account states that Orsini himself threatened to have the corpse exhumed and displayed publicly in full papal regalia.
According to different accounts, the College of Cardinals on the death of Gregory IX numbered between 12 and 14 cardinals. The number of cardinal electors who actually voted in the final scrutiny was only 10. At the time of Gregory IX's death, most of the cardinal electors who took part in the election were already present in Rome, and the two cardinals held prisoner by Frederick II were already captive in Naples. The two cardinals had been apprehended at sea aboard captured Genoese galleys, while traveling to a general council that Gregory IX had called for Easter 1241 to denounce Frederick II . Cardinal Colonna, however, was on one of his country estates near Palestrina when the Pope died. He had had a nasty fight with Gregory IX, and withdrew from the Curia. On his estate he had been holding consultations with the Emperor Frederick. When Gregory died, the Emperor, who was with his army at Grottaferrata, gave permission (licentia) for all cardinals outside Rome to return.
|Elector||Origins||Order||Title||Date of creation||by Pope||Notes|
|Raynaldus de' Conti||Jenne||Cardinal-bishop||Bishop of Ostia e Velletri||September 18, 1227||Gregory IX||future Pope Alexander IV|
|Romano Bonaventura||Roman||Cardinal-bishop||Bishop of Porto e Santa Rufina||1216||Innocent III||Not to be confused with the contemporary Saint Bonaventure|
|Goffredo da Castiglione||Milan||Cardinal-bishop||Bishop of Sabina||September 18, 1227||Gregory IX||Elected Pope Celestine IV|
|Stefano de Normandis dei Conti||Roman||Cardinal-priest||Title of S. Maria in Trastevere||1216||Innocent III||Archpriest of the Vatican Basilica; nephew of Innocent III|
|Giovanni Colonna||Roman||Cardinal-priest||Title of S. Prassede||February 18, 1212||Innocent III||The first Colonna cardinal|
|Sinibaldo Fieschi||Lavagna, Genoa||Cardinal-priest||Title of S. Lorenzo in Lucina||September 18, 1227||Gregory IX||Future Pope Innocent IV|
|Rainiero Capocci, O.Cist.||Todi||Cardinal-deacon||Deacon of S. Maria in Cosmedin||1216||Innocent III||Protodeacon of the Sacred College of Cardinals|
|Gil Torres||Spanish||Cardinal-deacon||Deacon of Ss. Cosma e Damiano||December, 1216||Honorius III|
|Riccardo Annibaldi||Roman||Cardinal-deacon||Deacon of S. Angelo in Pescheria||1237||Gregory IX||Rector of Campagna and Marittima; nephew of Cardinal Rinaldo Conti de Segni|
|Robert Somercotes||English||Cardinal-deacon||Deacon of S. Eustachio||1238||Gregory IX||Died during the sede vacante on September 26, 1241|
|Elector||Origins||Order||Title||Date of creation||by Pope||Notes|
|Giacomo da Pecorara, O.Cist.||Piacenza||Cardinal-bishop||Bishop of Palestrina||September 5, 1231||Gregory IX||Prisoner of Frederick II, Holy Roman Emperor|
|Oddone di Monferrato||Montferrat||Cardinal-deacon||Deacon of S. Nicola in Carcere Tulliano||September 18, 1227||Gregory IX||Prisoner of Frederick II, Holy Roman Emperor; allowed to join the election late, but returned to prison before the election.|
|Tommaso da Capua||Capua||Cardinal-priest||Title of S. Sabina||1216||Innocent III||Penitentiary and protopriest of the Sacred College; his participation is disputed because sources indicate that he died in 1239.|
|Peter of Capua the Younger||Amalfi||Cardinal-deacon||Deacon of S. Girogio in Velabro||1219||Honorius III||He may have died ca. 1236-1241.|
The main factions of cardinals were composed of the Gregorians (Rinaldo Conti de Segni, Sinibaldo Fieschi, and Riccardo Annibaldi, who supported the election of Romano Bonaventura), who wished to continue Gregory IX's hostility towards the Holy Roman Emperor. Frederick II naturally objected to the election of Cardinal Romano Bonaventura due to his "persecution" of the University of Paris while legate to France, his alleged debauching of Queen Blanche of Castile, and his role in the dispute between Gregory IX and the emperor. The majority, however, including the "Moderates of the Opposition" (including Giovanni Colonna, Robert Somercotes, and Rainiero Capocci, supported Cardinal Goffredo Castiglione,) who advised a policy of dealing with Frederick.
When neither side was able to reach a two-thirds majority, required by the Constitution of Alexander III, the cardinals wrote to Frederick II and requested him to release the two cardinals whom he held captive. After the conclave had begun, the Emperor Frederick had had the two cardinals brought from Naples to Tivoli. However, when summoned to the Emperor's presence, rather than agree to the Emperor's conditions, Cardinal Giacomo da Pecorara proceeded to excommunicate the Emperor yet once again. It was clear that the Cardinal would never cooperate, and he therefore remained in detention for two more years. Cardinal Oddone di Monferrato, however, was allowed to join the election, though he was required to leave hostages in his place and to promise to return to the Emperor's custody, unless he himself was elected pope or the deadlock continued. Frederick did not expect, of course, that the cardinls would elect Cardinal Oddo as pope; Frederick's own friends in the Conclave could and would prevent that. Nor did he want Cardinal Oddo to be elected. His real opinion of the Cardinal is revealed in a letter he wrote after the Battle of Giglio: as a Legate in England and France Oddo had conspired a good deal against the honor of the Emperor; he had raised a crowd of prelates to bring them to Rome to participate in Gregory IX's Council; in Genoa he had conspired against those Genoese who were supporters of Frederick; he had raised and armed a fleet to transport the prelates to Rome, and to reduce the Genoese. Cardinal Oddo was to be an instrument to break the deadlock in the meeting. Frederick II himself urged the cardinals to make a quick choice:
- "Like serpents you cling to the earth instead of raising yourself to the skies. Each of you is aiming at the tiara, and no one of you is willing to leave it to the other. Renounce the spirit of faction and of discord! Let the college of cardinals give by unanimous choice to Christendom a pope who will satisfy us and the empire, and whose election will be for the universal good."
The Emperor then, in September, returned to his kingdom by way of Campania, leaving the two cardinals at Tivoli under the custody of Tybboldus de Dragone.
The heat and shortage of food may have contributed to the death of Cardinal Somercotes, although the other members of the pro-Imperial faction alleged that he had been poisoned. Cardinal Fieschi's health also deteriorated severely, apparently causing the future pope to inch closer to death. The remainder of the cardinals were not allowed to leave the Septisolium for the funeral, nor were physicians or servants allowed to enter the building (where a sizable amount of excrement had begun to build up). Bonaventura would also die some sixteen months after the election, which the vivid narrations gratuitously attribute to the effects of the Election.
Cardinal Castiglione's advanced age and deteriorating health are thought to have contributed both to his status as papabile and his ultimate election, making him an ideal compromise candidate, "stop-gap", or "provisional Pope". More polemical sources describe Celestine IV as a "feeble, ignorant, old fanatic" who was "destitute of any other qualification". One commentator suggested that the cardinals "escaped by electing a dying man". Still others refer to him as "Orsini's candidate".
Celestine IV died on Sunday, November 10, 1241, just 17 days after his election, dying even before he had been enthroned. It is possible that the cause of death was dysentery, contracted in the Septasolium (Saepta Solis). It is speculated that had Celestine IV lived longer he "would in all likelihood have proven friendly to the emperor".
Pope Celestine was buried on the day after his death, according to the custom. But, even before the funeral, certain cardinals fled the city, and headed for Anagni, the home of Cardinal Rinaldo dei Conti di Segni. It is said (by Matthew of Paris) that only six or seven cardinals were left in the city. Cardinal Colonna, however, was seized by the Roman populace, who supported the Orsini, and imprisoned due to his association with King Frederick.
When confronted by a group of begging friars bearing a message from the Archbishop of York and Bishop of Lincoln, Frederick II reportedly said: "Who is hindering the welfare of the Church? Not I; but the stubborn pride and greediness of Romans. Who can wonder if I withstand the English and Roman Churches, which excommunicate me [as Oddone had done from England], defame me, and are always pouring forth money to do me wrong?" Soon after the conclave, the hostilities between the Guelphs and Ghibellines resumed around the Italian peninsula, on both land and sea. Although Frederick II was now free to crush the Lombards without a pope to oppose him, he soon diverted much of his cavalry and infantry north of the Alps where the Tartars had begun to seriously threaten his lands.
Thus began the longest sede vacante in the history of the Roman Catholic Church since the period between Pope Agatho and Pope Leo II (681-682). It took a year and a half before the cardinals were successful in reconvening in Anagni (Frederick II was in possession of Rome) and electing a successor to Celestine IV (due in no small part to Frederick II's continuing to keep da Pecorara and Oddone as hostages: choosing Cardinal Fieschi as Pope Innocent IV in 1243. Innocent IV breathed new life into the conflict against Frederick II, and after the emperor's death in 1250, excommunicated his son and heir, Conrad IV of Germany. Imperial influence in papal elections persisted until the papal election, 1268–1271, after which the Imperial party (then composed mostly of older cardinals) was all but extinguished within the College of Cardinals.
One contemporary account of mixed reliability is that of British chronicler Matthew Paris (c. 1200–1259), who claims that both his compatriot, Robert Somercotes, and Celestine IV died of poisoning; his works are more prized for their accounts of the Hohenstaufen struggles. Matthew was a friend of Cardinal Somercotes (who had once presided over the audientia litterarum contradictarum in Rome), and further claimed that Somercotes would have soon been elected pope himself had he survived. Such speculation appears from time to time in English literature; e.g. "the Italians were too hard for the honest Englishman, being made away by poison at the Holy Conclave, 1241," but it can be safely ignored. Accusations of poisoning of popes and cardinals, such as Innocent V and Adrian V, are a regular feature of chronicles in the 13th and 14th century.
By virtue of the cardinals being locked in, the election is sometimes referred to as the "first conclave" (even the "first formal papal Conclave"), although the formal procedures of the conclave would not be developed until after the papal election, 1268–1271, in the Constitution "Ubi Periculum" of Pope Gregory X (1274). Its provisions were first implemented in the papal conclave, January 1276. In fact, the practice of seclusion of the cardinal electors can perhaps even be traced back to the papal election, 1216, where the people of Perugia locked in the cardinals after the death of Pope Innocent III.
- Gregorovius is in error, giving November 1 as the date of the Election of Celestine IV; he was following the Annals of Piacenza and the Chronicle of Mailros. See the list of contemporary sources on the matter in August Potthast, Regesta pontificum Romanorum I , p. 940.
- Miranda, Salvador (1998). "Papal elections and conclaves of the 13th Century (1216–1294)".
- Gregorovius, 1906, p. 218.
- The Cardinals were not put in the Septizodium, a third-century nymphaeum which was mostly in ruins in 1241, and which never had any rooms attached to it. The New Topographical Dictionary of Ancient Rome (ed. L. Richardson) (Baltimore 1992), pp. 349-350, makes it clear that the Septizodium was only an elaborate water feature, without rooms or roof; "the upper storeys can have been accessible only by ladders, and there is no sign of a building of any sort behind this façade." A clue as to what is meant is given by a signature of the newly created Cardinal Silvius, ca. 1130: Silvius diac. S. Luciae iuxta Heligabalum: J. Watterich, Pontificum Romanorum Vitae II, 185. Heliogabalus, the early-third-century Roman Emperor, had built the Precinct of the Sun (Saepta Solis) not far from the Septizodium, at the foot of a street called the Clivus Scauri. It was in the Saepta Solis, or Septasolium, where the election took place. In 1152 a cardinal signs himself Radulfus, diaconus card. Sanctae Luciae in Septa solis; and in 1201 Leo sce. Lucie ad septa solis diac. card. See: The Septasolium (Saepta Solis)
- Augustin Demski, Papst Nikolaus III, Eine Monographie (Münster 1903), pp. 2-5. Richard Sternfeld, Der Kardinal Johann Gaetan Orsini (Papst Nikolaus III.) 1244-1277 (Berlin: E. Ebering 1905), pp. 1-7.
- Ryccardus de S. Germano, a contemporary writer, says: Eodem mense Augusti iussu imperatoris vastatores de regno aput Insulam pontis solarati et aput Sanctum Iohannem de Incarico, ut intrent Campaniam congregantur. Cardinales qui in Urbe ad papae electionem convenerant, per senatorem et Romanos apud Septisolium includuntur, ut ad creandum papam inviti procedant. "In that same month of August, while, by order of the Emperor, the destroyers from his kingdom, at Insula of Pons Solaris and at S. Giovanni de Incarico, were assembled so that they could enter Campania. The cardinals, who had assembled in Rome for the papal election, were closed up by the Senator and the Romans at the Septasolium, that, even unwillingly, they might proceed to electing a pope." For an evaluation of Ryccardus, see Karla Mallette, The Kingdom of Sicily, 1100-1250: A Literary History (Philadelphia: University of Pennsylvania Press, 2011), esp. p. 45-54.
- Abulafia, 1988, p. 350. This depends on the account published by K. Hampe in 1913
- Bordihn, 2005, p. 376.
- Baumgartner, 2003, p. 35.
- Rotberg, 2001, p. 58.
- The number of fourteen is given by Salvador Miranda Papal election of 1241 and K. Eubel, Hierarchia Catholica, vol. I, p. 6. Eubel's list of cardinals who actually carried out the Election (i.e. were present at the end of the Conclave) contains thirteen names, but omits Robert Somercote, who died before the election was completed; it also includes Peter of Capua, Deacon of S. Giorgio, whose participation is uncertain. The number of 12 or 13 appears from the prosopgraphy of the cardinals of that time by A. Paravicini Bagliani (Cardinali di curia e "familiae" cardinalizie. Dal 1227 al 1254, 2 vols., Padova 1972), who excludes Cardinal Peter of Capua. This discrepancy appears to be a matter of the difference between 'cardinals alive at the death of Gregory IX' and 'cardinals who cast a vote in the final scrutiny'.
- Kington-Oliphant, 1862, p. 303.
- Williams, 1908, p. 511.
- Ullmann and Garnett, 2006, p. 259.
- Ryccardus de S. Germano, p. 381, lines 29-30: Imperator ipse apud Criptam ferratam ponit castra sua, et in exterioribus Urbem divastat, et tunc de Gregorio papa quod obierit Romae 21 Augusti, pro certo accepit, de cuius licentia cardinales omnes qui extra Urbem fuerant, pro electione papae facienda ad Urbem redeunt. Gasquet, 1905, p. 199.
- A. Paravacini-Bagliani, Cardinali di Curia e 'familiae' cardializie dal 1227 al 1254 I (Padua, 1972), pp. 41-53.
- Ryccardus de S. Germano, Chronica, in G. Pertz (ed.), Monumenta Germaniae Historica Volume 19, 378, states, under the year 1239 : Aput Anagniam Thomas Capuanus Sancte Sabine presbyter cardinalis 15 Kal. Septembris [August 18] obiit. A. Paravicini Bagliani, Cardinali di curia e "familiae" cardinalizie I (Padova: Antenore 1972), p. 13, states correctly that he had died in 1239, between August 18 and August 22. Cf. S. Miranda: Cardinal Tommaso da Capua (note 2)
- A. Paravicini Bagliani, Cardinali di curia e "familiae" cardinalizie. Dal 1227 al 1254, I, p. 16 says that although commonly given year of his death is 1242, his last subscription of the papal bull took place in February 1236, and concludes that it is unlikely that died later than 1241. Paravicini Bagliani is relying on an argument e silentio, and carefully phrases his statement both to include and exclude Cardinal Peter as an elector.
- Ryccardus de S. Germano, Chronica, in Monumenta Germaniae Historica Scriptorum Tomus 19 (Hannoverae 1866), p. 381.
- Constantin Höffler, Albert von Beham und Regesten Papst Innocenz IV. (Stuttgart 1847), pp. 55-57: ...et Oddo de Todenengo, sancti Nycolai in carcere Tulliano diaconus cardinalis, qui diu legati fuerant in partibus transalpinis et contra honorem nostrum multipliciter machinati, praelatorum turba, quam dinumerare nemo poterat, pro celebrando Romae contra nos concilio e diversis provinciis convenerat, Januam venientes, et conspiratione facta cum Januensibus rebellibus nostris et armata ibidem copia galearum, cum quibus duci Romam et Januam reduci convenerant...
- Francis Aidan Gasquet incorrectly states that Pecorara was released as well, stating also that Oddone (who had excommunicated the emperor from England and raised funds with which Gregory IX had waged war on the emperor) returned to Frederick II's custody before the conclusion of the election. See Gasquet, 1905, p. 199. Henderson also claims that the two prisoners attended the election and thereafter returned to custody together. See Henderson, 1894, p. 395; Henderson is wrong.
- Henderson, 1894, p. 386.
- Cardinal Bonaventura died on February 21, 1243, according to the "Necrologio di S. Maria in Trastevere," in P. Egidi, Necrologi e libri affini della Provincia Romana (Roma 1908), p. 91. There is too much distance between the electoral meeting and his death to conjecture that the one caused the other. That would be an argument post hoc ergo propter hoc.
- Kington-Oliphant, 1862, p. 304.
- History of Popery, 1838, p. 138.
- Ambrosini and Willis, 1969, p. 267.
- It is perhaps imprecise, therefore, to state that Celestine IV "only wore the tiara sixteen days". See Michaud and Robson, 1881, p. 296.
- The statement that Celestine died of dysentery contracted in the Septasolium is pure speculation. There is no contemporary source that says so.
- Henderson, 1894, p. 385. There are numerous cases, however, in which Popes surprise their supporters by showing entirely opposite attitudes and policies than what was expected.
- Matthew of Paris, Volume IV, p. 194 Luard. Butler, 1906, p. 290.
- Kington-Oliphant, 1862, pp. 304-305, relying on Matthew of Paris.
- Kington-Oliphant, 1862, pp. 305-306.
- Butler, 1906, p. 290-291.
- Tobin and Wister, 2003, p. 54.
- Watt, 1995, p. 112.
- Wright and Neil, 1904, p. 525.
- Herbermann, Charles, ed. (1913). "Pope Innocent IV". Catholic Encyclopedia. New York: Robert Appleton Company.
- Baumgartner, 2003, p. 39.
- Rand, Edward Kennard (1932). "Osbert of Clare, the Sarum Breviary, and the Middle-English Saint Anne in Rime Royal". Speculum. Mediaeval Academy of America. 7: 106. doi:10.2307/2848329.
- Jane E. Sayers, Papal Government and England During the Pontificate of Honorius III (1216-1227) (Cambridge: Cambridge University Press, 1984), pp. 34-40. Cardinal Oddo and Cardinal Sinibaldo Fieschi had also been auditors litterarum contradictarum earlier in their careers. Peter Herde, Zur Audientia litterarum contradictarum und und zur "Reskripttechnik" ( Köln: Böhlau, 1973). Josef Teige, Beiträge zur geschichte der Audientia litterarum contradictarum (Prag: Dominicus, 1897).
- Dugmore, C. W. (1950). "On the Promotion of English University Clerks during the Later Middle Ages". Journal of Ecclesiastical History. Cambridge University Press. 1: 174. doi:10.1017/S002204690007233X.
- Welby, A. E. "17th century Account of Lincolnshire". Lincolnshire Notes and Queries (1898), p. 179.
- Kühner, 1958, p. 89. Pham, 2006, pp. 62-63. Duffy, 2006, p. 153.
- Bernardus Guidonis, in Ludovico Antonio Muratori, Rerum Italicarum Scriptores III, p.486], Perusinis causa electionis papae strictissime arctantibus cardinales ('the Perusines enclosed the cardinals very securely for the sake of the election of a pope'). That is the only reference in contemporary literature, and its meaning is vague. A. Bo. 1910. Encyclopædia Britannica. p. 828.
- Anonymous, A History of Popery. 1838. London: John W. Parker. pp. 116–120. (a superficial, polemical, anti-Roman tract).
- Baumgartner, Frederic J. 2003. Behind Locked Doors: A History of the Papal Elections. Macmillan. ISBN 0-312-29463-8.
- Bernardus Guidonis, "Vita Coelestini Papae IV," in Ludovico Antonio Muratori, Rerum Italicarum Scriptores Tomus Tertius (Mediolani 1723) p. 589.
- Bernardus Guidonis, "Vita Gregorii Papae IX," in Ludovico Antonio Muratori, Rerum Italicarum Scriptores Tomus Tertius (Mediolani 1723) p. 570-588.
- Bordihn, Maria R. 2005. The Falcon of Palermo. Atlantic Monthly Press. ISBN 0-87113-880-8.
- Butler, William Francis Thomas. 1906. The Lombard Communes: A History of the Republics of North Italy. C. Scribner's Sons.
- Duffy, Eamon. 2006. Saints and Sinners: a history of the popes. Yale University Press. ISBN 0-300-11597-0.
- Gasquet, Fracis Aidan. 1905. Henry the Third and the Church. G. Bell.
- Gregorovius, Ferdinand. 1906. History of the City of Rome in the Middle Ages. G. Bell. Volume V, part 1.
- Hampe, K., "Ein ungedruckter Bericht über das Konklave von 1241," Sitzungsberichte. Heidelberger Akademie der Wissenschaften,.phil. hist. Klasse 4 (1913) 1-31. (the single source of most of the lurid XX century stories of this papal election).
- Henderson, Ernest Flagg. 1894. A History of Germany in the Middle Ages. G. Bell and Sons.
- Hilpert, Hans Eberhard. 1981. Kaiser- und Papstbriefe in den Chronica Majora des Mattheus Paris Stuttgart, Publications of the German Historical Institute, London, 9.
- Huillard-Bréholles, J.-L.-A. (Editor). 1859-1860. Historia diplomatica Friderici Secundi Tomus V, Pars II (Parisiis: Henricus Plon 1859); Tomus VI. Pars I. a mense Septembri 1241 ad mensem Julium 1247 (Paris: Plon 1860).
- Kantorowitz, Ernest. 1931. Frederick the Second, 1194-1250. New York.
- Kington-Oliphant, Thomas Laurence. 1862. History of Frederick the Second, Emperor of the Romans. Macmillan.
- Kühner, Hans. 1958. Encyclopedia of the Papacy. Philosophical Library.
- Levillain, Philippe. 2002. The Papacy: An Encyclopedia. Routledge. ISBN 0-415-92228-3.
- Lewis, Suzanne. 1987. The Art of Matthew Paris in the Chronica Majora. Berkeley-Los Angeles. University of California Press.
- Luard, Henry Richards (editor), 1880. Matthaei Parisiensis, Monachi Sancti Albani, Chronica Majora Vol. IV. A.D. 1248 to A. D. 1258 (London: Longman 1880)
- Nicolaus de Curbio, O.Min., "Vita Innocentii Papae IV," in Ludovico Antonio Muratori, Rerum Italicarum Scriptores Tomus Tertius (Mediolani 1723) p. 592-592e.
- Parravicini Bagliani, A., Cardinali di curia e "familiae" cardinaliste, dal 1227 al 1254 Volume II (Padua 1972).
- Pham, John-Peter. 2006. Heirs of the Fisherman: Behind the Scenes of Papal Death and Succession. Oxford University Press. ISBN 0-19-517834-3.
- Rotberg, Robert I. 2001. Politics and Political Change: A Journal of Interdisciplinary History Reader. MIT Press. ISBN 0-262-68129-3.
- Tobin, Greg, and Wister, Robert J. 2003. Selecting the Pope: Uncovering the Mysteries of Papal Elections. Barnes & Noble Publishing. ISBN 0-7607-4032-1.
- Ullmann, Walter, and Garnett, George. 2003. A Short history of the papacy in the Middle Ages. Routledge. ISBN 0-415-30227-7.
- Watt, J. A. 1995. "Chapter 5: The Papacy" in The New Cambridge Medieval History. Cambridge University Press. ISBN 0-521-36289-X.
- Williams, Henry Smith. 1908. The Historians' History of the World. Hooper and Jackson.
- Williamson, Dorothy M. 1949. "Some Aspects of the Legation of Cardinal Otto in England, 1233-1241," English Historical Review 64. pp. 145–173.
- Wright, Charles Henry Hamilton, and Neil, Charles. 1904. A Protestant Dictionary. Hodder and Stoughton.
- Documents concerning the Elections of 1241 (Dr. J. P. Adams)