Carlo Odescalchi, (5 March 1785 – 17 August 1841) was an Italian prince and priest, Archbishop of Ferrara, cardinal of the Catholic Church and Vicar General of the Diocese of Rome. For years a close collaborator of popes Pius VII and Gregory XVI, in 1838 he renounced his titles in order to become a Jesuit. Early life A relative of Benedetto Odescalchi, who reigned as Pope Innocent XI from 1676 until 1689, Carlo was born in Rome, the second son of the noble Baldassare Erba-Odescalchi, a Prince of the Holy Roman Empire and Duke of Syrmia in the Kingdom of Hungary, and his wife Valeria Caterina Giustiniani, who also belonged to a family of nobles. Carlo was first educated at home by his father, but from 1798 to 1800 studied in a seminary in Hungary, where the family lived for a time in exile after fleeing from the invading armies of the French First Consul Napoleon Bonaparte. He had received the clerical tonsure in 1797 and was eventually ordained to the priesthood on 31 December 1808, celebrating his first Mass on the next day, 1 January. Having completed higher studies in Italy, in 1809 he was awarded a doctorate in utroque iure (both canon and civil law). After becoming acquainted with Joseph Pignatelli and subsequent to Pope Pius VII's restoration of the Society of Jesus, he planned on entering the Society and was given preliminary acceptance but gave up the attempt due to the resistance of his sister Vittoria, who desperately sought to live near her brother. Pius VII himself agreed with Vittoria and promised Carlo that he could enter at a more appropriate time, but after Vittoria's marriage three years later, Pius decided to keep Carlo and appointed him papal auditor. In Papal service Pius VII, following his release from France, sent Odescalchi to Olomouc in 1815 as a papal legate to Antonín Colloredo-Waldsee, and again in 1819 to bestow the cardinalatial red biretta on Archduke Rudolf of Austria. From 1815 to 1820, Odescalchi served as auditor of the Sacra Rota Romana for Austria, auditor of the pope, and canon of St. Peter's Basilica. On 10 March 1823, Pius VII appointed Odescalchi the Archbishop of Ferrara and also created him Cardinal Priest with the title of Santi Apostoli. Odescalchi was consecrated a bishop on the following 25 May by Cardinal Giulio Maria della Somaglia, with Cardinals Giuseppe della Porta