Pope Gregory IX, born Ugolino di Conti, was pope from March 19, 1227 to August 22, 1241.

The successor of Pope Honorius III (1216–27), he fully inherited the traditions of Pope Gregory VII (1073–85) and of his uncle Pope Innocent III (1198-1216), and zealously continued their policy of Papal supremacy.

Early life

Ugolino was born in Anagni. Date of his birth fluctuates in the sources between ca. 1145 and 1170.

He was created Cardinal Deacon of S. Eustachio by his cousin (not uncle) Innocent III in December 1198. In 1206 he was promoted to the rank of Cardinal Bishop of Ostia e Velletri. He became dean of the Sacred College of Cardinals in 1218 or 1219. He was also Cardinal Protector of the Order of Franciscans.

As Cardinal Bishop of Ostia he had been in the inner circle of Honorius III, and associated with the Pope's policy of accommodation with the formidable Hohenstaufen Emperor Frederick II (1220–50), whose lawyers in Naples and Capua asserted his position as universal temporal ruler, in the mold of Constantine.David Abulafia, Frederick II: a Medieval Emperor 1992. 480 pages. Oxford University Press, USA (November 1, 1992) ISBN 0195080408

Papacy

Gregory IX began his pontificate by suspending the Emperor, then lying sick at Otranto, for dilatoriness in carrying out the promised Sixth Crusade. The suspension was followed by excommunication and threats of deposition, as deeper rifts appeared – Frederick II's control of the Sicilian Church, his feudal obligations to the Pope, even his continued presence in Sicily. Frederick II publicly appealed to the sovereigns of Europe complaining of his treatment. Frederick II went to the Holy Land and skirmished with the Saracens to fulfill his vow, but was soon back in Italy, where Gregory IX had taken advantage of his absence by invading his territories. A consequent invasion of the Papal states in 1228 having proved unsuccessful, the Emperor was constrained to give in his submission and beg for absolution.

Although peace was thus secured (August 1230) for a season, the Roman people were far from satisfied; driven by a revolt from his own capital in June 1232, the Pope was compelled to take refuge at Anagni and invoke the aid of Frederick II. Gregory IX and Hohenstaufen came to a truce, but when Frederick II defeated the Lombard League in 1239, the possibility that he might dominate all of Italy, surrounding the Papal States, became a very real threat. A new outbreak of hostility led to a fresh excommunication of the emperor in 1239, and to a prolonged war.

Gregory IX denounced Frederick II as a heretic and summoned a council at Rome to give point to his anathema, at which Frederick II attempted to capture or sink as many ships carrying prelates to the synod as he could. Eberhard II von Truchsees, Prince-Archbishop of Salzburg in 1241 at the Council of Regensburg declared that Gregory IX was "that man of perdition, whom they call Antichrist, who in his extravagant boasting says, I am God, I cannot err." He argued that the Pope was the "little horn" of Daniel 7:8:

A little horn has grown up with eyes and mouth speaking great things, which is reducing three of these kingdoms--i.e. Sicily, Italy, and Germany--to subserviency, is persecuting the people of Christ and the saints of God with intolerable opposition, is confounding things human and divine, and is attempting things unutterable, execrable.

The struggle was only terminated by the death of Gregory IX on August 22, 1241. He died before events could reach their climax; it was his successor, aptly named Pope Innocent IV (1243-54) who declared a crusade in 1245 that would finish the Hohenstaufen threat.
This pope, being a remarkably skillful and learned lawyer, caused to be prepared Nova Compilatio decretalium, which was promulgated in numerous copies in 1234. (It was first printed at Mainz in 1473). This New Compilation of Decretals was the culmination of a long process of systematising the mass of pronouncements that had accumulated since the Early Middle Ages, a process that had been under way since the first half of the 12th century and had come to fruition in the Decretum compiled and edited by the papally-commissioned legist Gratian and published in 1140. The supplement completed the work, which provided the foundation for papal legal theory.

His Bull Parens scientiarum of 1231 resolved differences between the unruly university scholars of Paris and the local authorities, who had precipitated this crisis by high-handed actions. His solution was in the manner of a true follower of Innocent III: he issued what in retrospect has been viewed as the magna carta of the University, assuming direct control by extending papal patronage: his Bull allowed future suspension of lectures over a flexible range of provocations, from "monstrous injury or offense" to squabbles over "the right to assess the rents of lodgings".

Gregory IX believed the problem of heresy needed serious attention and was not content with leaving it to the bishops, who might have been lax, but extended central control in this essential area as well. In 1231, he established the Papal Inquisition to deal with it, although he did not approve the use of torture as a tool of investigation or for penance.

He appointed ten cardinals and canonized Saints Elizabeth, Dominic de Guzmán, and Anthony of Padua, and also Francis of Assisi, of whom he had been a personal friend and early patron. His encroachments upon the rights of the English Church during the reign of Henry III of England (1216-72) are well known; similar attempts against the liberties of the national church of France were supposedly the occasion of the Pragmatic Sanction of Louis IX of France (1226-70), now generally thought to be a 14th-century forgery.

Gregory IX was a principal figure in the cementing and institutionalizing of Church teaching that discriminated against Jews and condemned them to an inferior status in Christendom. In the 1234 Decretals, he invested the doctrine of perpetua servitus iudaeorum – perpetual servitude of the Jews – with the force of canonical law. According to this, Jews would have to remain in a condition of political servitude and abject humiliation until Judgment Day. The doctrine then found its way into the doctrine of servitus camerae imperialis, or servitude immediately subject to the Emperor's authority, promulgated by Frederick II. The second-class status of Jews thereby established would last until well into the 19th century.

He transformed a chapel to Our Lady in the church of Santa Maria del Popolo in Rome.

Gregory IX endorsed the Northern Crusades and attempts to conquer Orthodox Russia (particularly the Pskov Republic and the Novgorod Republic).Christiansen, Eric. The Northern Crusades. New York: Penguin Books, 1997. ISBN 0-14-026653-4 In the year 1232, Gregory IX requested the Livonian Brothers of the Sword to send troops to protect Finland, whose semi-Pagan people were fighting against
Novgorod Republic in the Finnish-Novgorodian wars, however, there is no known information if any ever arrived to assist.

Perhaps his most lasting action was a minor item: saying in his papal letter Vox in Rama of 1232 that cats were an instrument of the devil and a symbol of heresy. This led to a great reduction in the number of cats, which, a hundred years later, contributed to the quick spread of the Black Death plague, which killed 1/3 to 1/2 of the population of Europe.