How the process of electing the pope has changed throughout history

In the earliest centuries of the Church, the method for selecting the Bishop of Rome, who would later be known as the Pope, was typically quite informal and mirrored how other bishops were chosen.

The Pope was typically elected by the members of the clergy in Rome, with some participation of the Roman laity who could express approval or disapproval.

Often the choice was made by general acclamation or consensus in an assembly rather than by the secret ballot that we are familiar with today.

To add extra weight to the decision, neighbouring bishops usually oversaw the process.

Even though this was a somewhat democratic method, it sometimes led to some seriously heated disputes.

For example, as early as the year 217, a disagreement in Rome led to parallel elections and the creation of a rival antipope. 

Once the Roman Empire permitted the existence of, and then formally embraced, Christianity in the 4th century, the people in political authority began to exert their own influence on papal selections.

The powerful Emperor Constantine and his successors did not hesitate to involve themselves in the decisions if it meant that it would result in a particularly pliant candidate would become pope.

As a result, secular intervention could be one of the most decisive factors in times of the most contested elections.

For instance, when Pope Zosimus died in 418, a protracted and violent dispute over his successor motivated Emperor Honorius to step in; a decree was issued that if factions could not agree on a pope, a fresh election should be held to avoid widespread bloodshed.

Likewise, in 498, after two rival claimants (Symmachus and Laurentius) were elected by different groups, the Gothic King Theodoric the Great felt the need to intervene so as to adjudicate in favour of Symmachus to take the top spot.

To prevent such chaos from breaking out in the future, Pope Symmachus himself convened a synod in 499 which finally established that any candidate who received the majority of votes from the clergy should be considered the legitimate pope, and it expressly forbade any pre-election canvassing for support.

This was the earliest known written regulation on papal elections, and aimed at reducing the influence of corruption and thuggish behaviour among various factions who coveted the most powerful position in the Christian world. 

But this did not stop the government from begin involved. By the 6th and 7th centuries, the influence of the Eastern Roman (Byzantine) emperors was treated as a necessary step in the formalisation of the papal elections.

In fact, Emperor Justinian I claimed the right to approve the pope’s election before the new pope could be officially consecrated.

Practically, this meant the result of a papal election had to be sent from Rome to Constantinople, and the Church had to await the emperor’s confirmation, or potential rejection.

This process often caused lengthy delays, and sometimes vacancies of many months.

It also made papal candidates increasingly mindful of the important of seeking imperial favour before embarking as a papal candidate.

The requirement of imperial confirmation from Constantinople would continue until 684, when Pope Benedict II obtained approval from Emperor Constantine IV a relaxation of the rule so that papal electors did not have to await distant imperial approval.

By this time, it was becoming more difficult for the empire to exert pressure on the Church, as they faced increasing military pressure from the east. 

Meanwhile back in the West, the vacuum left by waning Byzantine power led the Frankish kings and later Holy Roman Emperors to assert their own role in its stead.

Most famously, in 800, Charlemagne was crowned as Emperor of the Romans. It was then expected that his Frankish realms would act as the military protectors of the papacy whenever it was in trouble.

By 824, Charlemagne’s successor, Emperor Lothair I, issued the Constitutio Romana, which required that the pope-elect swear loyalty to the emperor, and that no consecration could occur without imperial confirmation.

This effectively gave the Frankish Emperor a veto-like power over papal elections in the 9th century, much as the Byzantines had in prior centuries.

Therefore, many early medieval popes were often elected under the shadow of imperial oversight rather than by the free choice of the clergy alone. 

Despite these secular encroachments, the Church tried to maintain some autonomy in the election process.

The Lateran Council of 769, which was called by Pope Stephen III, explicitly limited papal candidates to be only from the ordained Roman clergy, such as priests or deacons, and barred laypeople from the actual voting.

After election by the clergy, however, the new pope was still presented to the people of Rome for a traditional acclamation and public approval.

This was meant to limit the growing influence of militarised Roman aristocracy in the picking popes, but it only resulted in angering powerful people in Rome.

So, as a political compromise, in 862 Pope Nicholas I held a synod that restored a role to the Roman nobility in papal elections by allowing the leading laymen of the city to have a say or witness in the process.

By the late 10th century, the pendulum had once more swung heavily back towards secular control: in 963, Emperor Otto I the Great of Germany had the Romans swear they would not elect a pope without his expressed consent.

He even deposed Pope John XII and installed his own candidate, Leo VIII. Similarly, in the early 11th century, Emperor Henry III effectively appointed a series of reform-minded popes which including Clement II, Damasus II, and Leo IX, without the normal election process.

These developments alarmed many within the church who resented the fact that non-church leaders were able to control the most important position in their organisation. 

The medieval period saw the papacy being able to successfully reassert control over its own election process again.

Specifically, the Gregorian Reform movement in the 11th century sought to free the Church from lay domination by reforming the process of the papal elections.

The most important turning point was the Papal Election Decree of 1059 under Pope Nicholas II.

It was known as In Nomine Domini, and it changed the electoral body by vesting the power to elect the Pope in a College of Cardinals.

These ‘cardinals' were the senior clergy of Rome, such as the cardinal-bishops, cardinal-priests, and cardinal-deacons.

It was argued that they were the most experienced, and therefore the most suitable, people in the church, and should be trusted with the selection more than anyone else.

Under this new system, the seven cardinal-bishops of the sees around Rome were to meet first and consider suitable candidates, then invite the rest of the cardinals to vote.

The decree specified that their choice should ideally be from among the Roman clergy unless no suitable candidate could be found locally.

Importantly, Nicholas II’s reform still allowed elements of earlier practice, since, after the cardinals made their choice, the result was to be presented to the clergy and people of Rome for assent.

However, this was now a formality to simply maintain the fiction of popular involvement.

The decree also subtly acknowledged the role of the Holy Roman Emperor by saying the election should consider the rights and prerogatives of the emperor, but it did not grant the emperor any direct say.

In practice, this meant notifying the emperor of the election outcome, rather than seeking his approval.

Indeed, after 1059, emperors could no longer nominate popes; at most they could attempt to influence cardinal electors behind the scenes.

Pope Gregory VII (elected 1073) was the last pope to actually seek confirmation from the emperor, and he soon entered into conflict with Emperor Henry IV during the Investiture Controversy anyway. 

Despite the 1059 decree, the 12th century was still a complicated time for papal elections.

The Investiture Controversy led to several disputed elections and the election of a number of antipopes.

For example, there were rival popes in 1118 (Gelasius II vs. Gregory VIII), in 1130 (Innocent II vs. Anacletus II), and later in the 1150s–1160s (Alexander III vs. Victor IV and others).

These disputes usually caused by factions of cardinals and their political backers who stubbornly disagreed on an acceptable candidate, which meant that sometimes each conducted their own elections while ignoring those of competing factions.

In response to ongoing troubles, Church councils in the 12th century introduced further reforms to fix the electoral process.

The Second Lateran Council in 1139 eliminated the requirement of obtaining the assent of the lower clergy or laity in papal elections.

From that point, the election was purely an internal affair of the cardinals, without any formal public ratification.

Then the Third Lateran Council in 1179 extended the right to vote to all cardinals, not just the cardinal-bishops, and it established that a two-thirds majority of the College of Cardinals was required to elect a pope.

This two-thirds rule was designed to ensure that any new pope had overwhelming support and, by so doing, discouraged dissenting minorities from setting up antipopes.

The council did not stipulate a specific procedure if a two-thirds majority could not be reached, but in essence it meant the cardinals must deliberate as long as necessary until consensus built around someone.

Interestingly, the two-thirds majority requirement introduced in 1179 remains a core rule all the way to the present, with only minor adjustments. 

It must be noted that by the High Middle Ages, the College of Cardinals was relatively small group which often only numbered 20 or 30 members, and sometimes even fewer.

This small electorate, combined with difficult travel conditions, meant that not all cardinals always arrived promptly for an election.

As a result, medieval conclaves could be quite prolonged, especially if factions were deadlocked in their deliberations.

A notorious case took place following the death of Pope Clement IV in 1268. The subsequent election dragged on for nearly three years (1268–1271) because the cardinals, split by French-Italian political tensions, could not agree on a candidate.

Eventually the authorities of the town of Viterbo, where the election was being held, took drastic action: they locked the cardinals in the episcopal palace, put them on meagre rations of bread and water, and even removed the building’s roof to expose them to the weather, in order to force a conclusion.

This resulted in the election of Pope Gregory X in 1271. 

Learning from this episode, Pope Gregory X decided to institutionalise such measures to prevent interminable elections.

At the Second Council of Lyons in 1274, he promulgated the constitution Ubi Periculum (“Where danger [lies]”).

This established the formal rules of the conclave for all future papal elections.

According to these new rules, the cardinals were to assemble no more than ten days after a papal death to begin the new election, and once assembled, they would all be locked in one closed area with no private rooms, under strict supervision.

They were allowed only one servant each and were cut off from outside communication.

Any outside message that arrived during a conclave had to be delivered openly in the presence of all.

Critically, Ubi Periculum introduced the idea of progressively worsening living conditions to incentivise a quick decision: after three days without an election, meals were to be limited to one per day; after five more days (i.e. eight days total without a pope), only bread, water, and wine would be provided.

Clearly, this was aimed at eliminating both external influences on the result as well as internal procrastination.

Any cardinal who tried to violate the enclosure or communicate secretly would be instantly excommunicated.

What is more, the secular authorities of the city hosting the conclave were obliged to enforce the enclosure and conditions.

This 1274 decree is now seen as the birth of the conclave system in the form essentially still used today for papal elections.

The very term conclave (from Latin cum clave, 'with a key') comes from these arrangements. 

The initial reaction of the cardinals to Gregory X’s conclave rules was surprisingly hostile.

The members of the Church felt the restrictions were too severe and impinged on their own dignities and freedoms.

Within a few years, in 1276, Pope Adrian V suspended the conclave regulations (though he died shortly thereafter), and Pope John XXI formally revoked Ubi Periculum later in 1276.

As a result, the next few papal elections reverted to the older style. Unsurprisingly, lengthy deadlocks returned.

From 1276 to 1294 there were multiple protracted sede vacante periods (papal vacancies), including one lasting two years and nine months without a pope.

Eventually, the return of chaos in the elections finally convinced the Church to once more reinstate the conclave system.

Following the election of Pope Celestine V in 1294, the new pontiff re-established the 1274 conclave rules as binding.

His successor, Boniface VIII, ensured these rules were incorporated into Canon Law.

From that point on, every papal election, with a few rare exceptions due to external disruptions, has been conducted in conclave. 

So, toward the end of the medieval period in 14th century, the procedure for papal elections was relatively well-defined.

However, this did not eliminate political influences so much as contain them within the College.

Secular rulers continued to influence cardinals through diplomacy or threats, and factions within the College, who were often aligned with French interests vs. Italian or Imperial interests, could lead to some contested outcomes.

The most significant crisis was the Great Western Schism (1378–1417). In 1378, under pressure from an angry Roman populace to elect an Italian after the period of the Avignon papacy, the cardinals chose Urban VI, but many soon regretted it and a dissenting group elected a rival, Clement VII, who returned to Avignon.

This split the Church for nearly 40 years. The normal conclave process broke down because different groups of cardinals held separate elections.

The schism was only healed by resorting an unusual procedure: the Council of Constance was convened from 1414 to 1418 to end the crisis.

It deposed or accepted the resignation of the existing claimants and in 1417 the council arranged a unique election for a new pope.

All legitimate cardinals from every faction participated, and to satisfy the broader Church, additional delegates from each major nation also had votes.

The subsequent election of Martin V effectively reaffirmed the unified College of Cardinals to elect the pope and no further schisms of similar magnitude have arisen since.

The Council of Constance did also discuss reforms to prevent future schisms or abuses: one idea, that was not permanently implemented, was to limit the number of cardinals to 24 and to require that they be drawn from various regions to make the College less subject to one nation’s influence.

After Constance, the conclave system resumed, and by the mid-15th century the papal election process was back to the norms set in the 13th century. 

At this stage in history, the College of Cardinals became increasingly international with more cardinals from outside Italy, especially from France and Spain. As a result, it was often split by political factions.

During the 15th and 16th centuries, European monarchs, particularly the Kings of France and Spain, and the Holy Roman Emperor, treated the papal election simply as another affair of state, since the pope had significant influence over Christendom.

These powers did not have a formal vote, but they negotiated with and pressured cardinal-electors.

Popes of this era were often members of influential Italian families like the Medici, Borgia, and della Rovere, and their elections could often be swayed by family alliances.

While the conclave rules mentioned before kept the proceedings secret, increasing political influence entered through the cardinals themselves, since many of them were relatives of important rulers or owed favours to their secular patrons.

For example, in the conclaves of the early 16th century, the College was frequently divided into the ‘French faction’ versus the ‘Imperial (Habsburg/Spanish) faction’, and each was expected to promote particular candidates that were aligned with their monarch’s interests. 

One persistent problem in Renaissance conclaves was simony: the buying and selling of votes.

The most notorious case was the conclave of 1492. In this event, Cardinal Rodrigo Borgia was elected as Pope Alexander VI, and, shortly after, rumours emerged that he had effectively bribed other cardinals with vast sums of money and promises of lucrative church appointments.

Although simony was expressly forbidden by Church law, enforcement of this was difficult behind the closed doors of a conclave.

So, to tackle this, Pope Julius II, who himself had been involved in the politics of that same conclave, issued the papal bull Cum tam divino on 14 January 1505 that declared that if a papal election was obtained through simony, the election was null and void, even if the chosen cardinal was otherwise canonically elected.

This was a strong deterrent. Julius II’s bull was formally confirmed by the Fifth Lateran Council in 1513 just after Julius’s death and, subsequently, overt simony in papal elections became much rarer. 

One of the most often forgotten developments in the late Renaissance period was the formal acceptance of the right of secular exclusion, known as the jus exclusivae.

This meant that it became an established custom that certain Catholic monarchs could each veto one papal candidate in a conclave.

Typically, the crowns of France, Spain, and Austria (Holy Roman Empire) held this privilege, by which they would give a secret instruction to one of their cardinals that if a particular candidate, whom the monarch found objectionable to his national interests, seemed likely to be elected, the cardinal was to announce the monarch’s ‘exclusion’ of that candidate.

The excluded man would then voluntarily withdraw or at least the College would avoid voting for him further, out of respect for the monarch’s wish.

This was not explicitly a church law, but the practice was ‘tacitly accepted’ by the Church as a reflection of certain political realities in the wider European world.

For example, in the conclave of 1644, Spain effectively vetoed Cardinal Sacchetti because he was perceived as pro-French, and in 1669–1670, France excluded Cardinal Altieri.

While this interference was obviously a contradiction of the ideal of an independent election, popes tolerated it to maintain good relations with the great Catholic powers. 

Then, the popes of the late 16th and 17th centuries continued to refine the conclave procedures and related rules.

Pope Sixtus V’s 1587 bull limiting the College to 70 cardinals was one such measure.

It was intended to ensure that the electorate did not become too large and unwieldy, but it also capped the influence any one pope could have by creating new cardinals.

Then, as mentioned, Pope Gregory XV in 1621–1622 issued two bulls, Aeterni Patris Filius (1621) and Decet Romanum Pontificem (1622), which introduced strict secret ballots that were confirmed with oaths.

Under this, each cardinal would write the name of his chosen candidate on a paper ballot, while disguising his handwriting in doing so and signing with an encoded identifier.

Ballots were then counted by scrutineers, and if no one received the required two-thirds majority, more ballots would be held, up to four per day.

Gregory XV even prescribed special ceremonies and prayers to invoke the Holy Spirit’s guidance during the voting.

The net effect was that by the mid-17th century, the mechanics of papal elections had assumed the form they would keep into modern times. 

As a result, by the 18th century, the structure of papal conclaves was firmly established, but the Enlightenment and the rise of modern states changed the relationship between the papacy and Catholic monarchies significantly.

During this time, various popes in the 18th and 19th centuries issued minor adjustments to conclave arrangements, often in response to unusual circumstances.

For example, when Pope Pius VI died in 1799 while a prisoner of the French during the turmoil of the Napoleonic wars, the ensuing conclave of 1799–1800 had to be held in exile in Venice, under Austrian protection.

Afterward, rules were clarified about how to conduct a conclave outside Rome if needed.

Additionally, because during that conclave the cardinals were scattered by war, the waiting period before opening a conclave was extended, and it eventually settled at 15 days after the pope’s death, to allow far-flung cardinals time to travel. 

The final abolition of secular intervention in papal elections came in the early 20th century.

In the conclave of 1903, Emperor Franz Joseph of Austria exercised the veto one last time, through Cardinal Puzyna, to exclude Cardinal Mariano Rampolla, who was Leo XIII’s Secretary of State, from consideration.

The shocked College of Cardinals then elected Cardinal Giuseppe Sarto, who became Pope Pius X ad he immediately issued the constitution Commissum Nobis (1904) which banned the jus exclusivae from that point forward.

He decreed that any cardinal who conveyed a secular veto or even revealed one would be excommunicated and that any such interference was to be ignored by the members. 

Another important change that Pius X introduced was to remove the automatic invalidation of a simoniacal election that Julius II had decreed.

Pius X lifted the penalty that would have made a simony-tainted election null, reasoning that once a pope is elected, even if by illicit means, the Church should accept the outcome to avoid uncertainty.

However, the penalty of potential excommunication for individuals guilty of simony remained.

This meant that it was, in reality, a legal tweak to safeguard the office’s legitimacy, not done to condone bribery.

This was also later reaffirmed by Pope John Paul II in 1996, to ensure no one could challenge a pope’s validity by accusing the conclave of bribery. 

Next, the Code of Canon Law of 1917 explicitly stated that cardinals must all be ordained because, by that time, the last non-priest cardinal had died in 1899.

Pope Pius XII, in a constitution issued in 1945, adjusted the majority needed to account for the possibility of a cardinal voting for himself.

Pius XII essentially required a two-thirds majority, rounded up (two-thirds plus one if the math was not whole) to prevent a candidate from tipping the scales by counting his own vote. 

The next major change in the composition of the conclave came under Paul VI. He Recognised that the College of Cardinals had grown much larger and more international.

Pius XII and John XXIII had both elevated many new cardinals, which surpassed the old limit of 70.

So, Paul VI issued two important rules: in 1970, he declared that cardinals who had reached the age of 80 could no longer participate in papal elections.

This was to make sure that only those in reasonably active service and health would undertake the rigours of a conclave and to prevent extremely elderly cardinals from holding decisive power.

Then, in 1975, Paul VI set the maximum number of cardinal-electors at 120. This was decided on somewhat arbitrarily but was based on the College’s size at that time.

Subsequent popes have generally adhered to this cap, though occasionally exceeding it slightly when creating cardinals, although natural attrition will soon bring the number back under 120.

The cardinal-electors are now a subset of the College, and are predominantly archbishops active around the world, rather than every living cardinal. 

When Pope John Paul II updated the laws governing papal succession with Universi Dominici Gregis in 1996, he included a controversial clause: if the cardinals were deadlocked after numerous ballots, at least 30 ballots, which would be about 7 days of voting, they could vote to allow election by an absolute majority (more than half) instead of two-thirds.

This was a departure from centuries of practice introduced as a safety valve in case a conclave became interminably stalled.

However, this provision raised concerns about legitimacy, since a pope elected by a slim majority might reopen factional wounds.

In fact, before it was ever used, it was rescinded by Pope Benedict XVI in 2007.

Benedict also restored the requirement that at no stage can the two-thirds rule be relaxed.

Interestingly, he also made a minor timing change in 2013. After his own resignation on the 28th of February, which was the first papal resignation since Gregory XII in 1415, he allowed the cardinals to start the conclave a bit earlier than the 15-day waiting period, since they were all already assembled in Rome. 

On the 12th of March 2013, the conclave elected his successor after five ballots: Cardinal Jorge Mario Bergoglio of Argentina was elected as the 266th pope, who took the name Francis.

He was the first Jesuit pope, the first from the Americas, and the first non-European pope in over 1,200 years.

His election followed the modern conclave procedure codified in Universi Dominici Gregis, which included a maximum of 120 cardinal electors under the age of 80, secret ballots requiring a two-thirds majority, and strict seclusion rules: the result of 2000 years of refined church practice.