Pope Innocent IX died on December 30, 1591 only two months into his pontificate. This created the fourth sede vacante in the one and half years since the death of Pope Sixtus V,. No similar situation had occurred since 1276–1277.
Fifty four out of the sixty four cardinals participated in this conclave:
Alfonso Gesualdo (created cardinal on February 26, 1561) – Cardinal-Bishop of Ostia e Velletri; Dean of the Sacred College of Cardinals; Prefect of the S.C. of Ceremonies; Prefect of the S.C. of Rites; Cardinal-protector of the Kingdom of Portugal and the Kingdom of Sicily
Innico d'Avalos d'Aragona, O.S.Iacobis. (February 26, 1561) – Cardinal-Bishop of Porto e Santa Rufina; Sub-dean of the Sacred College of Cardinals
Marco Antonio Colonna (March 12, 1565) – Cardinal-Bishop of Palestrina; Librarian of the Holy Roman Church
Tolomeo Gallio (March 12, 1565) – Cardinal-Bishop of Frascati
Gabriele Paleotti (March 12, 1565) – Cardinal-Bishop of Sabina; Archbishop of Bologna
Michele Bonelli, O.P. (March 6, 1566) - Cardinal-Bishop of Albano; Prefect of the S.C. of the Bishops and Regulars; Cardinal-protector of the Order of Dominicans
Markus Sitticus von Hohenems (February 26, 1561) - Cardinal-Priest of S. Maria in Trastevere; Protopriest of the Sacred College of Cardinals; Archpriest of the patriarchal Lateran Basilica
Ludovico Madruzzo (February 26, 1561) - Cardinal-Priest of S. Lorenzo in Lucina; Bishop of Trento; Cardinal-protector of Germany and Spain
Girolamo Simoncelli (December 22, 1553) - Cardinal-Priest of S. Prisca; Administrator of the see of Orvieto
Giulio Antonio Santori (May 17, 1570) - Cardinal-Priest of S. Bartolomeo all’Isola; Grand Inquisitor of the Supreme S.C. of the Roman and Universal Inquisition; Archbishop of Santa Severina; Cardinal-protector of the Order of Capuchins and of the Greek Catholic Church
Girolamo Rusticucci (May 17, 1570) - Cardinal-Priest of S. Susanna; Vicar General of Rome; Camerlengo of the Sacred College of Cardinals; Cardinal-protector of the Order of Cistercians
Nicolas de Pellevé (May 17, 1570) - Cardinal-Priest of S. Prassede; Archbishop of Sens and Archbishop of Reims; Cardinal-protector of Ireland
Pedro de Deza (February 21, 1578) - Cardinal-Priest of S. Girolamo degli Schiavoni
Alessandro Ottaviano de' Medici (December 12, 1583) - Cardinal-Priest of SS. Giovanni e Paolo; Archbishop of Florence
François de Joyeuse (December 12, 1583) – Cardinal-Priest of SS. Trinita al Monte Pincio; Archbishop of Toulouse; Cardinal-protector of the Kingdom of France
Giulio Canani (December 12, 1583) - Cardinal-Priest of S. Anastasia; Bishop of Modena
Anton Maria Salviati (December 12, 1583) – Cardinal-Priest of S. Maria della Pace
Agostino Valier (December 12, 1583) - Cardinal-Priest of S. Marco; Bishop of Verona
Vincenzo Lauro (December 12, 1583) - Cardinal-Priest of S. Clemente; Bishop of Mondovi; Cardinal-protector of Scotland
Filippo Spinola (December 12, 1583) - Cardinal-Priest of S. Sabina; Legate in Spoleto
Jerzy Radziwiłł (December 12, 1583) – Cardinal-Priest of S. Sisto; Bishop of Kraków
Scipione Lancelotti (December 12, 1583) - Cardinal-Priest of S. Salvatore in Lauro; Secretary of the Apostolic Briefs
Enrico Caetani (December 18, 1585) – Cardinal-Priest of S. Pudenziana; Camerlengo of the Holy Roman Church; Latin Patriarch of Alexandria; Prefect of the Congregation for French affairs
Giovanni Battista Castrucci (December 18, 1585) - Cardinal-Priest of S. Maria in Aracoeli
Domenico Pinelli (December 18, 1585) - Cardinal-Priest of S. Crisogono; Archpriest of the patriarchal Liberian Basilica; Papal legate in Perugia and Umbria; Cardinal-protector of the Order of Carmelites
Ippolito Aldobrandini (December 18, 1585) - Cardinal-Priest of S. Pancrazio; Grand penitentiary
Girolamo della Rovere (November 16, 1586) - Cardinal-Priest of S. Pietro in Vincoli; Archbishop of Turin
Girolamo Bernerio, O.P. (November 16, 1586) - Cardinal-Priest of S. Maria sopra Minerva; Bishop of Ascoli-Piceno; Cardinal-protector of the Order of Servites
Antonio Maria Gallio (November 16, 1586) - Cardinal-Priest of S. Agnese in Agone; Bishop of Osimo
Costanzo Buttafoco da Sarnano, O.F.M.Conv. (November 16, 1586) – Cardinal-Priest of S. Pietro in Montorio
Benedetto Giustiniani (November 16, 1586) - Cardinal-Priest of S. Marcello; Prefect of the Tribunal of the Apostolic Signature of Grace; Legate in Marche; Vice-protector of the Kingdom of France
William Allen (August 7, 1587) – Cardinal-Priest of S. Silvestro a Martino ai Monti
Scipione Gonzaga (December 18, 1587) – Cardinal-Priest of S. Maria del Popolo; Latin Patriarch of Jerusalem
Antonio Maria Sauli (December 18, 1587) - Cardinal-Priest of S. Stefano al Monte Celio
Giovanni Evangelista Pallotta (December 18, 1587) - Cardinal-Priest of S. Mateo in Merulana; Archpriest of the patriarchal Vatican Basilica
Giovanni Francesco Morosini (July 15, 1588) - Cardinal-Priest of S. Maria in Via; Bishop of Brescia; Cardinal-protector of Hungary
Francesco Maria Del Monte (December 14, 1588) – Cardinal-Priest of SS. Quirico e Giulitta
Agostino Cusani (December 14, 1588) – Cardinal-Priest of S. Lorenzo in Pansiperna
Mariano Pierbenedetti (December 20, 1589) - Cardinal-Priest of SS. Marcellino e Pietro
Gregorio Petrocchini, O.E.S.A. (December 20, 1589) – Cardinal-Priest of S. Agostino
Paolo Emilio Sfondrati (December 19, 1590) – Cardinal-Priest of S. Cecilia; Legate a latere in Bologna and Romagna; Prefect of the Supreme Tribunal of the Apostolic Signature of Justice
Ottavio Paravicini (March 6, 1591) – Cardinal-Priest of S. Giovanni a Porta Latina; Bishop of Alessandria
Andreas von Österreich (November 19, 1576) – Cardinal-Deacon of S. Maria Nuova; Protodeacon of the Sacred College of Cardinals; Bishop of Constance and bishop of Brixen; Cardinal-protector of Austria
Simeone Tagliavia d'Aragonia (December 12, 1583) – Cardinal-Deacon of S. Maria degli Angeli; Vice-protector of the Kingdom of Spain
Francesco Sforza di Santa Fiora (December 12, 1583) - Cardinal-Deacon of S. Maria in Via Lata; Legate in Romagna
Alessandro Peretti Montalto Damasceni (May 13, 1585) - Cardinal-Deacon of S. Lorenzo in Damaso; Vice-Chancellor of the Holy Roman Church; Legate in Bologna; Cardinal-protector of the Kingdom of Poland; Cardinal-protector of the orders of Benedictines and Celestines
Girolamo Mattei (November 16, 1586) - Cardinal-Deacon of S. Eustachio; Prefect of the S.C. of the Tridentine Council
Ascanio Colonna (November 16, 1586) – Cardinal-Deacon of S. Maria in Cosmedin
Federico Borromeo (December 18, 1587) – Cardinal-Deacon of S. Nicola in Carcere Tulliano
Guido Pepoli (December 20, 1589) – Cardinal-Deacon of SS. Cosma e Damiano
Ottavio d'Aquaviva (March 6, 1591) – Cardinal-Deacon of S. Giorgio in Velabro; Legate in Campagna and Marittima
Odoardo Farnese (March 6, 1591) – Cardinal-Deacon of S. Adriano
Flaminio Piatti (March 6, 1591) – Cardinal-Deacon of S. Maria in Domnica
Giovanni Antonio Facchinetti de Nuce (December 18, 1591) – Cardinal-Deacon with no deaconry assigned; Secretary of State and Superintendent general of the Papal States
Twenty three electors were created by Sixtus V, thirteen by Gregory XIII, seven by Pius IV, five by Gregory XIV, four by Pius V, one by Innocent IX and one by Pope Julius III.
Ten cardinals were absent:
Gaspar Quiroga y Vela (December 15, 1578) – Cardinal-Priest of S. Balbina; Archbishop of Toledo; Inquisitor General of the Spanish Inquisition
Rodrigo de Castro de Lemos (December 12, 1583) – Cardinal-Priest of SS. XII Apostoli; Archbishop of Seville
Philippe de Lenoncourt (November 16, 1586) – Cardinal-Priest of S. Onofrio; Prefect of the S.C. of Index
Pierre de Gondi (December 18, 1587) – Cardinal-Priest of S. Silvestro in Capite; Bishop of Paris
Filippo Sega (December 18, 1591) – Cardinal-Priest with no title assigned; Bishop of Piacenza; Legate in France
Albrecht VII Habsburg (March 3, 1577) – Cardinal-Deacon of S. Croce in Gerusalemme; Inquisitor General of the Portuguese Inquisition; Viceroy of Portugal
Charles III de Bourbon de Vendôme II (December 12, 1583) – Cardinal-Deacon with no deaconry assigned; Archbishop of Rouen
Andrzej Batory (July 4, 1584) – Cardinal-Deacon of S. Angelo in Pescheria; Bishop of Warmia
Hughes de Loubenx de Verdalle, O.S.Io.Hieros. (December 18, 1587) – Cardinal-Deacon of S. Maria in Portico; Grand Master of the Knights Hospitaller
Charles III de Lorraine-Vaudémont (December 20, 1589) – Cardinal-Deacon of S. Agata in Suburra; Bishop of Metz; Papal Legate in Lorraine
Five of these were created by Gregory XIII, four by Sixtus V and one by Innocent IX.
Divisions in the Sacred College and the main candidates
The Sacred College of Cardinals was divided into several factions. The strongest of them was the Spanish faction with Madruzzo as unofficial leader. They supported the interests of king Philip II of Spain. Their candidate was Giulio Antonio Santori, head of the Roman Inquisition, called Cardinal S. Severina. His candidature was supported also by the "Sixtine" party, which included the old favourites and circle of Pope Sixtus V; their leader was Sixtus's cardinal-nephew, Alessandro Peretti de Montalto, Vice-Chancellor of the Church. Montalto supported Santori as a tactical manoeuvre and his real candidate was Aldobrandini. There was also a numerous group of cardinals that openly opposed Santori. Most of them were the old circles of Gregory XIII and Pius IV and their leaders were Sforza, Hohenems and Marcantonio Colonna.
Since in the last two conclaves the candidates supported by Spain had won, it was generally thought that also this time only pro-Spanish papabile had any prospects of winning the election. Besides Santori, only Madruzzo, Tolomeo Gallio, Paleotti, Marco Antonio Colonna and Aldobrandini were acceptable to Spain and it seemed clear that the new Pope would be one of them.
The conclave began on January 10, 1592. The next morning Madruzzo and Montalto together with their adherents tried to elect Santori by acclamation, but their plan had failed due to strong opposition from Hohenems and his party. Afterwards the normal voting procedures were followed. Every day a vote took place, with the following results:
• January 11 – Santori – 28, Aldobrandini - 11
• January 12 – Santori – 23, Aldobrandini - 18
• January 13 – Santori – 23, Aldobrandini - 18
• January 14 – Santori – 24, Aldobrandini - 9
• January 15 – Santori – 21, Aldobrandini - 13
• January 16 – Santori – 22, Aldobrandini - 13
• January 17 – Santori – 23, Aldobrandini - 13
• January 18 – ?
• January 19 – Santori – 23, Aldobrandini - 12
• January 20 – Santori – 22, Aldobrandini - 15
• January 21 – Santori – 23, Aldobrandini - 17
• January 22 – Santori – 23, Aldobrandini - 12
• January 23 – Madruzzo – 21, Santori – 18
• January 24 – Santori – 18, Aldobrandini and Madruzzo – 16 each
• January 25 – Santori i Aldobrandini – po 19
• January 26 – Santori – 18, Madruzzo - 16
• January 27 – Santori – 21, Madruzzo – 16
• January 28 – Aldobrandini – 17, Santori and Madruzzo – 15 each
• January 29 – Santori – 17, Aldobrandini – 16
Santori received the greatest number of votes in almost each ballot, but was not able to secure the required majority of two thirds and support for him gradually diminished. Eventually on January 29 Cardinal Montalto decided to switch to support the candidature of Ippolito Aldobrandini and was able to secure significant votes for him. Madruzzo then accepted that the opposition against him was too strong and switched to Ippolito Aldobrandini as more acceptable than Santori. This was the decisive moment of this conclave.
On January 30, 1592 Cardinal Ippolito Aldobrandini was unanimously elected to the papacy and took the name of Clement VIII. On February 2 he was consecrated to the episcopate by Cardinal Alfonso Gesualdo, bishop of Ostia e Velletri and dean of the College of Cardinals. Seven days later he was solemnly crowned by Francesco Sforza di Santa Fiora, deacon of S. Maria in Via Lata.
