Papal conclave, 1513  

Raphael, Painting of Leo X with cardinals Giulio de' Medici and Luigi de' Rossi 

Other names  Accession of Leo X; Giovanni de'Medici papal election; Accession of Giovanni de' Medici;^{[1]} Election of Leo X 
Participants  Giovanni de' Medici (elected Pope Leo X), Raffaele Riario, Domenico Grimani, Jaime Serra I Cau, Marco Vigerio della Rovere, Francesco Soderini, Alessandro Farnese (future Pope Paul III), Luigi d'Aragona, Tamás Bakócz, Marco Cornaro, Francisco de Remolins, Niccolò Fieschi, Adriano di Castello, Robert Guibé, Leonardo Grosso della Rovere, Carlo Domenico del Carretto, Sigismondo Gonzaga, Sisto Gara della Rovere, Christopher Bainbridge, Antonio Maria Ciocchi del Monte, Pietro Accolti, Achille Grassi, Matthäus Schiner, Bandinello Sauli, Alfonso Petrucci, 
Location  Rome 
Date  1513 
Result  Elected Giovanni de'Medici as Pope Leo X to succeed Pope Julius II. 
The papal conclave, 1513 elected Giovanni de'Medici as Pope Leo X to succeed Pope Julius II.
Contents 
Twentyfive of the living thirtytwo cardinals entered the conclave on March 3^{[2]} or March 4.^{[3]} The first several days were spent on the drafting of a conclave capitulation, regulating the procedures of the conclave and agreeing on the benefices that would be granted to the various cardinals, including a payment of 1,500 ducats by whomever was elected, upon the completion of the election.^{[3]} Among the conclavists was Giacomo di Brescia, the private physician required by Cardinal Medici; Giacomo, despite his plea, was not permitted to leave early once his services were no longer required.^{[4]}
The first scrutiny took place on March 10 after a ceremonial reading of Julius II's bull against simony.^{[4]} The voting itself took place in the no longer extant chapel of S. Niccolo da Bari.^{[5]} As the ranking cardinaldeacon, Medici himself was charged with the counting of the ballots.^{[6]} Cardinal Serra i Cau (called Alborense) received thirteen votes on the first ballot.^{[4]} Although Pirie subscribes this outcome to chance (see below), Roscoe argues that Alborense had the support of the older cardinals, while the younger, and particularly the royal and noble cardinals supported Medici.^{[6]}
That night at dinner, Cardinal Medici and Cardinal Raffaele Riario (the two leading papabile) were seen in closer conversation although no other observer was able to make out the subject.^{[7]} Even before the vote took place the next morning, a rumor spread among the cardinals as to the outcome of the conversation, and every other cardinal flocked to Medici's cell to congratulate him.^{[8]} Trollope claims that every cardinal did such because "it is ill voting against a man today who is to be the despotic master of your fate and fortunes on the morrow".^{[8]}
Medici was unanimously elected on the first scrutiny in the morning.^{[8]} A window which had been boarded closed for the conclave was smashed open and Cardinal Alessandro Farnese (future Pope Paul III) announced Medici by his chosen papal name, Leo X.^{[6]}
Florentine banker Filippo Strozzi the Younger accompanied Medici to Rome for the conclave; Strozzi's brother (a disciple of Savonarola) claimed that: "inasmuch as the latter aspired not without good reason to the Papacy, it was likely enough that he might have to vail himself of Filippo's credit".^{[9]}
According to Valerie Pirie's The Triple Crown (1936):
Prof. Anthony Lo Bello of Allegheny College tested the ex
ante probability of Pirie's account, assuming that the
cardinals assumed that all but a handful of the assembled
twentyfive cardinals were not among the papabile, and thus were not perceived as
being able to receive the requisite seventeen votes, and that only
a smaller number of these, m, had absolutely no
supporters.^{[11]}
Lo Bello further assumes that r cardinals participated in
the strategy that Pirie outlines and calculates the probabilities
for 17 ≤ r ≤ 25, using factorials.^{[11]}
The probability of Pirie's account occurring in terms of r
and m was:^{[11]}
and the probability of a candidate receiving seventeen votes
was:
Lo Bello concludes that the probability of Pirie's account is <1% for reasonable values of r and m, and that, were Pirie's account to be correct, the "shock" of the cardinals was misjudged because the probability of actually electing a pope with this method was far less, <0.1%.^{[12]}
Twentyfive cardinals participated in the election:

Six more cardinals chose not to participate in the conclave:
Four more had been excommunicated by Julius II, and thus could not participate (all were reinstated by Leo X):


