From 1309 to 1377, the popes of the Catholic Church did not reside in Rome. Instead, they lived in Avignon, a city in what is now southern France, under the shadow — and often the influence — of the French crown. This period, sometimes called the “Babylonian Captivity” of the papacy in reference to the Israelites’ exile in the Old Testament, remains one of the strangest chapters in the history of the church.

Why the Popes Left Rome

Rome in the early fourteenth century was a dangerous and unstable place, plagued by violent feuding among aristocratic families and lacking the infrastructure to reliably support a papal court. When the French archbishop Bertrand de Got was elected Pope Clement V in 1305, he chose not to travel to Rome at all, and in 1309 he settled the papal court in Avignon, a city that, while not technically part of France, sat well within its political orbit.

A Golden Cage

Clement’s successors continued the arrangement, and Pope Benedict XII began construction of the massive Palais des Papes, a fortress-like palace that still dominates Avignon’s skyline today. The Avignon papacy was, in many ways, an efficient and well-administered period for the church bureaucracy; the papal court developed sophisticated systems of finance and record-keeping. But it came at a steep cost to the papacy’s independence and reputation, as critics throughout Europe — including the poet Petrarch, who compared Avignon to a den of corruption — increasingly viewed the popes as puppets of the French monarchy.

The Return to Rome

Pressure to return to Rome grew steadily, driven in part by figures like St. Catherine of Siena, who wrote urgently to Pope Gregory XI urging him to bring the papacy home. Gregory finally did so in 1377, ending the Avignon period. But his death the following year triggered an even greater crisis.

The Western Schism

In 1378, a disputed papal election produced two rival claimants to the papal throne — one in Rome and one back in Avignon — each with their own supporters among the crowned heads of Europe. This event, known as the Western Schism, would eventually produce a third rival claimant and would not be fully resolved until the Council of Constance in 1417. The Avignon papacy and the schism that followed badly damaged the prestige of the papal office and fed a growing appetite for church reform that would eventually erupt, a century later, in the Protestant Reformation.

On November 27, 1095, Pope Urban II stood before a vast crowd gathered outside the cathedral of Clermont in central France and delivered one of the most consequential sermons in Christian history. Chroniclers say the crowd erupted with cries of “Deus vult!” — “God wills it!” — and within months, tens of thousands of men from across Western Europe had taken a vow to march to the Holy Land. The First Crusade had begun.

The Council’s Original Purpose

The Council of Clermont was not originally convened to launch a war. It was primarily a church synod focused on internal reform, part of the broader movement known as the Cluniac reforms, which sought to combat simony (the buying and selling of church offices), enforce clerical celibacy, and reassert the independence of the church from secular rulers who had grown accustomed to appointing bishops and abbots. Urban spent much of the council addressing these disciplinary matters before turning, on its final day, to the appeal that would define it.

Urban’s Call to Arms

Urban’s sermon responded to an urgent appeal from the Byzantine Emperor Alexios I Komnenos, whose empire was under pressure from Seljuk Turkish advances in Anatolia. Urban called on the knights of Western Christendom to set aside the internal warfare that had long plagued feudal Europe and instead direct their martial energy toward liberating Jerusalem and the holy places of the East from Muslim rule, promising that those who died on the campaign would receive remission of their sins.

An Unexpected Mass Movement

Urban likely anticipated a modest, professional force of knights. What followed instead was a much larger and more chaotic mass movement, including the disastrous “People’s Crusade” led by the preacher Peter the Hermit, in which thousands of poorly armed and poorly organized commoners set out for the Holy Land and were largely destroyed before reaching their destination. The main armies of knights fared better, capturing Antioch in 1098 and, after a brutal siege, Jerusalem itself in July 1099.

A Movement That Outlived Its Founder

Urban II died in 1099, just two weeks after Jerusalem fell, before news of the victory could reach him. But the movement he launched would continue for two more centuries, through a further eight major Crusades of varying success, reshaping relations between Christianity and Islam, contributing to (and later worsening) the rift between Eastern and Western Christianity, and leaving a legacy that remains deeply contested and consequential in the modern world.

On July 16, 1054, a delegation from Pope Leo IX, led by Cardinal Humbert of Silva Candida, walked into the Hagia Sophia in Constantinople during a liturgy and placed a papal bull of excommunication on the high altar, targeting Patriarch Michael Cerularius. Days later, Cerularius responded in kind, excommunicating the papal legates. This dramatic exchange is traditionally remembered as the moment of the Great Schism — the definitive split between the Latin Church of the West and the Greek-speaking Orthodox Church of the East.

A Divide Centuries in the Making

The events of 1054 were less a sudden break than the visible culmination of a rift that had been widening for centuries. Rome and Constantinople had grown apart linguistically, culturally, and politically ever since the empire itself split into Western and Eastern halves. By the time of the schism, the two churches disagreed on a number of significant matters.

The Filioque Controversy

Perhaps the most contentious theological issue was the filioque clause — a Latin phrase meaning “and the Son” that the Western Church had added to the Nicene Creed, stating that the Holy Spirit proceeds from the Father “and the Son,” rather than from the Father alone. Eastern theologians viewed this as both a theological error and an illegitimate unilateral change to an ecumenical creed that no single church had the authority to alter.

Authority, Liturgy, and Culture

Beyond the filioque, the churches clashed over the scope of papal authority. Rome increasingly claimed universal jurisdiction over all Christendom, a claim the East rejected, holding instead that authority rested collectively with the ancient patriarchates and ecumenical councils. Liturgical differences — such as the Western use of unleavened bread in the Eucharist versus the Eastern use of leavened bread — became flashpoints as well, alongside disputes over clerical celibacy and the proper date of Easter.

Mutual Excommunication, Not Immediate Rupture

Contemporaries did not necessarily view the events of 1054 as a permanent, irrevocable split; the mutual excommunications technically applied only to the individuals involved, not to the churches as a whole. But the rift deepened over the following centuries, especially after the catastrophic Fourth Crusade in 1204, when Latin crusaders sacked Constantinople itself, an act of violence against fellow Christians that Orthodox Christians have never forgotten.

A Wound Still Being Addressed

The mutual excommunications of 1054 were formally lifted only in 1965, when Pope Paul VI and Ecumenical Patriarch Athenagoras I issued a joint declaration expressing regret and removing them from memory, as part of the ecumenical spirit encouraged by the Second Vatican Council. Full communion between Rome and Constantinople, however, has never been restored, and the Great Schism remains the deepest and longest-standing division in Christian history.