World Religions › Medieval › Great Schism between East and West
Roman Catholic Church and the papacy
Latin West, distinct after 1054; papacy far older· Religion or tradition· Judaism, Christianity & Islam
Historical recordConfirmed by archaeology, outside sources or contemporary records.
The largest Christian church, about 1.4 billion members, led by the pope, the bishop of Rome, whom Catholics regard as Saint Peter's successor.
See it on the World Religions map →What it is
Catholics believe Jesus made Peter the rock of his church and that the popes inherit his authority, defined in 1870 as infallible when solemnly teaching on faith and morals. Rome's bishop gained leadership of the Latin West as the Western Roman Empire fell. Catholic life centers on seven sacraments, above all the Mass, plus devotion to Mary and the saints. It became distinct from Orthodoxy after 1054, and the Protestant Reformation split it again in the 1500s.
Why it matters
For a thousand years it was the West's main institution of learning, law and charity, founding universities and hospitals; today most Catholics live in the Americas, Africa and Asia.
Sources and history
Papal archives and council decrees, the Vatican's yearly statistics (Annuario Pontificio) and Pew surveys. Leo XIV, elected in 2025, is the first pope from the United States.
Questions and debates
When Rome first had a single bishop is debated; many historians think a group of elders led it until about the mid-100s, though Catholics trace an unbroken line from Peter.
Inside this (2)
Connections (10)
▸Roman Catholic Church and the papacy displaced Norse gods: Odin, Thor and ValhallaHistorical record
The connection
Missionaries and kings tied to the Latin Church converted Scandinavia between about 800 and 1100. Rulers such as Harald Bluetooth of Denmark and Olaf Tryggvason and Olaf Haraldsson of Norway adopted Christianity and imposed it, often by force, and Iceland's assembly voted to convert in 1000. Temples gave way to churches, and the old gods survived mainly in stories.
When and where
Denmark, Norway, Sweden and Iceland, about 820–1100: the monk Ansgar's missions from the 820s, Harald's Jelling stone (c. 965), Iceland's Althing (1000), Uppsala's temple ending around 1100.
Historical evidence
Runestones and early church sites, Adam of Bremen's chronicle (1070s), Icelandic sagas, and graves showing a shift from pagan grave goods to Christian burial.
Questions and debates
How fast ordinary people converted is debated; Christians wrote down the Eddas in the 1200s, so how much Christian writers reshaped Norse myth is unclear.
▸Augustine of Hippo shaped the theology of Roman Catholic Church and the papacyHistorical record
The connection
Augustine's writings became the backbone of Western Catholic theology: original sin inherited from Adam, grace as God's free gift, sacraments valid even when given by sinful priests, and history as a struggle between the 'City of God' and the earthly city. Medieval theologians, including Aquinas, built on him.
When and where
Hippo, Roman North Africa (modern Annaba, Algeria), where he was bishop 395–430; Confessions about 400, City of God 413–426.
Historical evidence
About 5 million words of his writings survive; councils such as Orange (529) and Trent (1545–1563) draw on him, and the Church names him a Doctor of the Church.
Questions and debates
Luther and Calvin also claimed Augustine, and Catholics and Protestants still debate whose reading of his teaching on grace is truer; Orthodox churches give him less weight.
▸Roman Catholic Church and the papacy launched The CrusadesHistorical record
The connection
The Crusades were papal projects. Popes called them, offered crusaders indulgences (release from the penalties of sin), and placed their property under church protection while they were away. Urban II's 1095 speech at Clermont set the pattern. Later popes also called crusades against Muslims in Spain, pagans in the Baltic and heretics like the Cathars in France.
When and where
Clermont, France, November 1095; Pope Urban II, followed by Innocent III and other popes through the 1200s.
Historical evidence
Papal bulls such as Innocent III's Quia Maior; several surviving accounts of Urban's speech; and church records of crusade taxes and vows.
Questions and debates
Exactly what Urban said at Clermont is uncertain, since the surviving accounts differ and were written years later.
▸Thomas Aquinas became chief theologian of Roman Catholic Church and the papacyHistorical record
The connection
Aquinas's blend of faith and reason gradually became the church's standard theology. He was canonized in 1323 and named a Doctor of the Church in 1567. The Council of Trent drew heavily on his work, and Pope Leo XIII's 1879 encyclical Aeterni Patris made his thought the model for Catholic seminaries. Catholic natural-law teaching still relies on him.
When and where
Paris and Naples in the 1200s; later recognition in 1323 (canonization), 1567 (Pius V) and 1879 (Leo XIII).
Historical evidence
Papal documents, including Aeterni Patris and the 1917 Code of Canon Law, which told seminaries to teach by Aquinas's method and principles.
Questions and debates
Some of his ideas were caught up in the Paris condemnations of 1277; theologians still debate how strictly Catholics should follow his system today.
▸Vatican and St. Peter's Basilica is the seat of Roman Catholic Church and the papacyHistorical record
The connection
The pope, as bishop of Rome, leads the Catholic Church from the Vatican. Catholics believe he is the successor of Peter, whose tomb is honored beneath St. Peter's Basilica. Popes lived mainly at Rome's Lateran Palace until the 1300s and settled at the Vatican after returning from Avignon in 1377. Since 1929 Vatican City has been a sovereign state.
When and where
Vatican Hill, Rome; papal residence since the late 1300s; the 1929 Lateran Treaty was signed by Cardinal Gasparri for Pope Pius XI and by Mussolini for Italy.
Historical evidence
Papal records, the Lateran Treaty, and the Holy See's diplomatic relations with more than 180 countries.
Questions and debates
Historians debate how early Rome's bishop held authority over all churches; Orthodox and Protestant Christians reject claims of papal supremacy.
▸Roman Catholic Church and the papacy led early Global Christian missions and empireHistorical record
The connection
Papal bulls of 1493 divided newly reached lands between Spain and Portugal, refined by the 1494 Treaty of Tordesillas; later bulls gave their crowns control of church appointments there in return for spreading the faith. Catholic orders, especially Franciscans, Dominicans and Jesuits, led the first wave of missions. From 1622 Rome's Propaganda Fide office coordinated missions directly.
When and where
From 1493 onward; Pope Alexander VI; the Jesuits, founded 1540; missions from Mexico and Peru to Goa, Japan and the Philippines.
Historical evidence
Papal bulls such as Inter caetera; mission archives in Rome; Jesuit letters; and baptism records across the Spanish and Portuguese empires.
Questions and debates
Historians debate how far the church restrained colonial abuses versus justified them; the Vatican formally repudiated the 'Doctrine of Discovery' in 2023.
▸Afro-Atlantic faiths: Vodou, Santería, Candomblé blended African spirits with saints of Roman Catholic Church and the papacyHistorical record
The connection
In Catholic colonies, enslaved Africans were baptized but kept honoring their own spirits by pairing them with saints who shared traits or imagery. Santería's Shango was linked to Saint Barbara and Babalú-Ayé to Saint Lazarus; Vodou's Ogou to Saint James. Catholic brotherhoods (cabildos, irmandades) gave Africans legal space to gather, and many devotees still attend Mass.
When and where
Cuba, Haiti and Brazil, 1600s–1800s, within Spanish, French and Portuguese Catholic colonies.
Historical evidence
Colonial church and brotherhood records; saint images on altars; and fieldwork documenting the pairings, which vary by region and house.
Questions and debates
Whether saints were a mask to fool slaveholders or became a real fusion is debated; some modern practitioners reject Catholic elements entirely.
▸Protestant Reformation broke from Roman Catholic Church and the papacyHistorical record
The connection
Reformers rejected the pope's authority, most sacraments, monastic vows and purgatory, and rulers seized church lands. Rome excommunicated Luther in 1521. Within a generation much of northern Europe had left the Roman Church, and the split became permanent, ending the Latin West's religious unity.
When and where
Germany, Switzerland, Scandinavia, England, Scotland and the Netherlands, 1517–1560s; Pope Leo X's 1520 bull Exsurge Domine condemned Luther.
Historical evidence
Papal bulls, Protestant confessions, records of dissolved monasteries, and the 1555 Peace of Augsburg recognizing Lutheran states.
Questions and debates
Catholics and Lutherans signed a 1999 joint declaration narrowing their dispute on justification; how much division remains is still discussed.
▸Council of Trent and the Catholic Reformation reformed Roman Catholic Church and the papacyHistorical record
The connection
Trent tightened discipline and clarified teaching: bishops had to live in their dioceses, and each diocese was to have a seminary. The Roman Catechism (1566), Missal (1570) and a revised Latin Bible (1592) followed. Reforming bishops like Charles Borromeo of Milan put it into practice. This 'Tridentine' Catholicism lasted until Vatican II.
When and where
Trent, 1545–1563; carried out by Popes Pius IV and Pius V, Charles Borromeo and new orders like the Jesuits.
Historical evidence
The decrees, the catechism and missal; seminary foundation records; and bishops' visitation reports showing reforms in parishes.
Questions and debates
How quickly and evenly the reforms spread is debated; in many regions they took a century or more to reach ordinary parishes.
▸Second Vatican Council modernized Roman Catholic Church and the papacyHistorical record
The connection
The council reshaped everyday Catholic life: Mass in local languages with the priest facing the people, larger roles for laypeople, acceptance of religious freedom, and openness to other Christians and the modern world, while keeping core doctrine. Bishops were to share responsibility with the pope, a principle called collegiality.
When and where
St. Peter's Basilica, four sessions in the autumns of 1962–1965; Popes John XXIII and Paul VI; the revised Mass took effect in 1969–70.
Historical evidence
The 16 council documents, the 1970 Roman Missal, and decades of surveys of Catholic practice.
Questions and debates
Whether the council caused the Western drop in Mass attendance and priestly vocations, or simply coincided with the 1960s, is debated; traditionalist groups rejected parts of it.