Conclave (Lat. con, with, and clavis, a key, because from their strict seclusion its inmates as it were unam habent clavem communens) is applied
(1.) to the apartments in which the cardinals of the Roman Catholic Church meet to elect a new pope; and
(2.) to the assembly itself convened for this object. The place of assembling was frequently changed until 1455, from which date to 1823 the conclave was held in the Vatican palace; since 1823 the Quirinal palace has been used for this purpose. When necessary, however, another place, even if without the city of Rome, may be designated. Little chambers, technically called cells, are prepared for the separate accommodation of each cardinal and his attendants, which are assigned by lot, and those falling to the occupancy of cardinals created by the late pope are draped with some purple material as a badge of mourning, while green is used for the others. The coat of arms of each cardinal is affixed to his cell. When a pope dies, ten days are allowed, for the obsequies, for the arrival of absent cardinals, and for the preparations above mentioned for the conclave, together with the selection of persons styled conclavists, who are to enter the conclave as servants of the cardinals (two to each, or, if the cardinal be very old, sickly, or of princely birth, three), masters of ceremonies, confessors, clerks, physicians, carpenters, masons, barbers, and other servants. The prescribed time having elapsed, the cardinals and conclavists attend the mass of the Holy Ghost, formerly in St. Peter's, lately in St. Sylvester's church. The papal ordinances governing the conclaves are read, to the strict observance of which all who are to enter the conclave are sworn. Then the cardinals, with their conclavists, proceed solemnly to the apartments prepared, and repair severally to their cells, where they receive visits until evening from persons not of their number. At the third signal from the bell, about three hours after sunset, all not belonging to the conclave are excluded, and all the entrances except one are walled up, the windows also, except so much as may be necessary for air and light. The excepted entrance is closed by double locks and strictly guarded, admission being allowed to none except the absent cardinals. No egress is allowed except by permission of the conclave itself in case of grave illness. The theory is that all communication between those within and persons without in regard to the pending election must be prevented; but these precautions have not always secured their end. In spite of the law, there is frequent correspondence between the cardinals within and their political friends without. The decree of Gregory X prescribed that, if a choice was not made by the cardinals within three days, for the next five days only one dish at noon and evening should be allowed to each, and after that time only bread, wine, and water; but this rigid regimen was modified somewhat by Clement VI (1351). The execution of these regulations is entrusted externally to the civil authorities of the place where the conclave is held, and internally to the officers appointed by the conclave.'
Prior to the latter half of the 11th century, the choice of the bishop of Rome was the joint prerogative of the clergy and people, exercised, we may suppose, at first directly, though subsequently the popular participation in the election appears to have been through some representative body; while the supreme secular power asserted its authority by requiring that the election should receive its sanction, the origin, doubtless, of the right exercised by certain Catholic governments (France, Spain, and Austria), and claimed by Italy (Naples) and Portugal, of each excluding from the papal throne some particular cardinal, a right, however, to be exercised before an election, and limited to one veto at each conclave. By a decree of Pope Nicholas II (In nosmine Domini), 1059, the election of pontiff was given to the cardinal bishops, the other cardinals, and the clergy, the people merely approving it. By a further decree of Alexander III (1179), the choice was vested exclusively in the college of cardinals, with the proviso that the concurrence of two thirds of the cardinals present should constitute a legal election, the assent of clergy and people being no longer required. The Council of Lyons (1274), under the auspices of Gregory X, promulgated a constitution minutely prescribing the forms to be observed in regard to such elections, which were to be made in conclavi clauso, so as to shut out secular influence. These three instruments furnish the organic laws and regulations, both of franchise and ceremonials, which, without fundamental change, are still in force in papal elections.
It is laid down as a settled principle that no pope can appoint his successor, and that every cardinal, however recently made such, provided he has taken deacon's orders, may participate in a conclave, though under papal censure, suspension, interdict, or excommunication.
According to the bulls of Gregory XV (AEterni Patris Filius and Decet Romanum Pontiifcem), confirmed by that of Urban VIII (ad Romani Pontjicis providenz tiam), the choice must be made in one of three ways, viz., by inspiration, compromise, or ballot. Election by inspiration is when all the electors spontaneously (per quasi inspirationem), without any previous concert, proclaim the same person for the office. Examples of such elections are given by early ecclesiastical writers, as that of Fabianus (Euseb. Hist. Eccles. 6:29), but in modern times none such has occurred. Election by compromise is when, in default, of agreement themselves, the cardinals delegate to a select number of their body, with or without conditions, authority to choose a pope, as was the case in the electtion of Clement V. The ordinary way, however, is by ballot. In this method, after the usual morning mass, each cardinal (when the conclave is assembled in the balloting-room or chapel), invoking Christ as witness to the purity of his intentions in the vote, deposits in the chalice on the altar a square paper, folded at opposite corners so as to conceal the voter's name and mot. to (which, once selected, must be adhered to), while the name of the person voted for is written on the open central space. These ballots are then examined in turn by three cardinals, appointed scrutatores, and the numbers taken, which must agree with that of the cardinals present, all being required to vote, and are filed to await the result. If any one has received just two thirds, the folded ends are opened to see that he has not voted for himself, which is not allowable. If no one has attained the required majority, the conclave proceeds in the afternoon session, after the hymn Veni Creator Spiritus, to try the process called acceding (accessus), in which each cardinal may give a supplementary vote, in the words accedo domino cardinali, to any one who received votes in the first process from others than the accedent; those declining to change the, morning's choice write nemini. If the supplementary votes for any, added to the morning's votes for the same, do not make up the two thirds 'majority, the papers are burned, and the same process of balloting is repeated the next day. When the requisite majority is given, the papers are examined to see that no cardinal has voted twice for the same person, and that the mottoes of the evening and morning vote tally; then the recipient of the highest vote equaling or exceeding two thirds is declared duly elected. On his acceptance the work of the conclave strictly ends, for the newly elected is deemed to be legally pope, with all his prerogatives and powers; he is invested with the pontifical robes, receives the homage of the cardinals, adopts his official name, and is proclaimed from, a reopened balcony window to the people by the cardinal dean, in the words Annuntio vobis gaudium magnum. Papam habemus Eminentissimum ac Reverendissimum — , qui sibi imposuit nomen — , and the shouts of the people are recorded as their assent, still, in theory, necessary to an election. The other ceremonies belonging to the inauguration follow in due order. — Ferraris, Bibliotheca Canonica, etc., art. Papa; Herzog, Real-Encyklopadie, art. Papstwahl; Ranke, History of the Papacy (see Index); North British Review, Dec. 1866, art. Conclaves; Petruccello della Gattina, BISTOIRE DIPLOMATIQUE DES CONCLAVES (Paris, 1865, 2 vols. 8vo); Cartwright, Papal Conclave (Lond. 1867). SEE CARDINALS; SEE POPE.