One of the primary duties of the Cardinals of the Catholic Church is the election of the Bishop of Rome who becomes thereby the Supreme Pontiff of the Church. The election is held in what is termed the conclave. The name is derived from the Latin cum (with) and clavis (key), and implies the fact that the cardinals are locked together in a room until a new pontiff has been chosen. This form of papal election began in 1274 and is considered the third period in the historical evolution of choosing the successor to St. Peter. Central to the full understanding of the conclave is the firm belief that the entire process of election is guided by the Holy Spirit.
In the early Church, new Bishops of Rome were chosen in the manner customarily used in the other dioceses, that is, the clergy, with the people of the diocese, elected or chose the new bishop in the presence of the other bishops in the province. This was a simple method, but it became impractical as the Christian population grew in size and there arose rival claimants and a certain hostility between the upper classes (the patricians) and the lower classes (the plebeians), each of whom had their own candidates. This situation created considerable upheaval in Rome as demonstrated by the riots accompanying the contested elections of Pope St. Damasus I (366-384) and the antipope Ursinus in 366. Such was the violence that the prefect of the city was called in to restore order.
On the basis of these disturbances, the Roman emperors began to involve themselves in the elections by guaranteeing proper procedure and ensuring free voting by the clergy in cases where two claimants had emerged. This intervention launched a long period of secular interference that would continue, to various degrees, until 1903. The so-called barbarian kings often supervised elections until the sixth century when the Byzantines reconquered Italy. The emperors not only demanded tribute from the popes but also retained the right of confirmation, a practice that routinely created long delays, as word would have to be sent to Constantinople (later Ravenna) to request approval. The last pope to seek confirmation from imperial authorities was Gregory III in 731. After this time, the popes sought the protection of the Franks, and in 769, Pope Stephen III convened a synod at Rome that confirmed the decree of 502 (under Symmachus) that laypeople should no longer vote for the popes and that only higher clerics should be considered eligible.
While making elections more efficient, the decrees did not remove the troublesome Roman nobility and their ambitions toward the papacy from 843 and the decline of the Frankish Empire. The next centuries saw such ruthless families as the Crescentii and Tusculani scheme to have their candidates elected, freely murdering those popes who displeased them and deposing others. A major reform was achieved in 1059 when Pope Nicholas II decreed that the cardinal bishops should choose the popes, a procedure modified by the Third Lateran Council (1179), which declared an end to distinctions among the three orders of cardinals in terms of voting, and requiring that a candidate receive a two-thirds majority.
The new need of a majority complicated many elections as a two-thirds plurality would often be quite difficult to reach owing to competing international interests among the cardinals. Vacancies were prolonged by squabbles, and sickly candidates were picked as compromises while negotiations would take place among the factions. After the death of Pope Clement IV in 1268, for example, three years passed until the eighteen cardinals gathered at Viterbo could agree on Pope Gregory X (r. 1271-1276), and this only after the citizens of the city reduced them to bread and water and tore the roof off the palace in which they were residing. Gregory introduced changes through the Second Council of Lyons (1272) to speed up elections, inaugurating the system of the conclave. It remained essentially unchanged until 1975. In that year, Pope Paul VI issued the apostolic constitution Romano Pontifici Eligendo (October 1) which stipulated various requirements for the conclave. Among these were: only cardinals may be electors; their number is limited to one hundred twenty, with each cardinal allowed to bring two or three assistants; while not essential for validity, it is the recognized form of election; three forms are acceptable: acclamation (acclamatio), compromise (by which certain cardinals are named delegates and are given power to act on behalf of the others); and balloting; if the person chosen is not a bishop, he is to be ordained to the episcopacy immediately (if a bishop, he is pope at once); secrecy is to be carefully observed; all ecumenical councils are immediately adjourned; and, if no one is elected after three days, one day is to be spent in prayer and meditation. New legislation regarding papal elections and church government during a vacancy of the Holy See was promulgated by Pope John Paul II on Feb. 23, 1996, in the apostolic constitution Universi Dominici Gregis (“Shepherd of the Lord’s Whole Flock”). Among the changes that were introduced was the call for heightened security in preventing electronic surveillance and the provision that after a set number of unsuccessful ballots, the cardinals may elect the new pope by a simple majority vote.
The last election not held in the Vatican (the Sistine Chapel) was in 1846 (Pius IX), which took place at the Quirinal Palace. The last pope not a cardinal at the time of his election was Urban VI (1378-1389); the last by compromise was John XXII (r. 1316-1334); and the last by acclamation was Gregory XV (1621-1623).