13.3 Patriarch and Papacy: The Church and the Call to Crusade

The Church and the Call to Crusade

The East-West Schism of 1054 split Christianity into two branches that remain divided today. Understanding this split is key to grasping why Pope Urban II's call for the First Crusade in 1095 found such a receptive audience, and how religious authority shaped medieval warfare.

East-West Schism Factors

The schism didn't happen overnight. Tensions between the Western Church (based in Rome) and the Eastern Church (based in Constantinople) had been building for centuries over theology, politics, and culture.

Theological differences:

• Filioque clause controversy: The Western Church added the word filioque ("and the Son") to the Nicene Creed, claiming the Holy Spirit proceeded from both the Father and the Son. The Eastern Church held that the Holy Spirit proceeded from the Father alone. This sounds like a small wording change, but it touched the core doctrine of the Trinity and became a major flashpoint.
• Iconoclasm: The Eastern Church went through periods of destroying or banning religious images and icons, viewing them as a form of idolatry. The Western Church supported the veneration of images as devotional aids. The Eastern Church eventually restored icons at the Second Council of Nicaea (787), but the decades of dispute left lasting resentment between the two churches.

Political and cultural differences:

• The Pope in Rome and the Patriarch of Constantinople increasingly clashed over who held supreme authority in the Christian world. The Pope claimed universal jurisdiction over all Christians (the doctrine of papal supremacy), while the Patriarch saw himself as an equal among the five major bishops, or pentarchy, with no single leader above the rest.
• The Western Church conducted its liturgy and theology in Latin; the Eastern Church used Greek. This language barrier made cooperation harder and deepened mutual misunderstanding over time.

The break itself:

In 1054, Cardinal Humbert, leading a delegation sent by Pope Leo IX, placed a bull of excommunication on the altar of the Hagia Sophia against Patriarch Michael Cerularius of Constantinople. The disputes centered on the filioque, the use of unleavened bread in the Western Eucharist, and jurisdictional authority. Patriarch Michael then excommunicated the papal delegation in return. This mutual excommunication formalized the division between the Roman Catholic Church (centered in Rome) and the Eastern Orthodox Church (centered in Constantinople). That split persists to this day.

Pope Urban II's First Crusade Call

At the Council of Clermont in 1095, Pope Urban II delivered a sermon calling for a military expedition to reclaim the Holy Land (Jerusalem and surrounding areas) from Muslim control. This moment transformed European politics and religion for centuries.

Motivations for the First Crusade:

• Reclaiming sacred sites: Jerusalem held enormous significance for Christians. Sites like the Church of the Holy Sepulchre (believed to be the location of Jesus's burial and resurrection) and the Via Dolorosa were under Muslim rule. Jerusalem had been in Muslim hands since the 630s, but the more recent Seljuk Turkish conquests disrupted the relative stability that earlier Muslim rulers had maintained.
• Protecting pilgrims: Christian pilgrims traveling to the Holy Land reportedly faced harassment and danger, particularly after the Seljuk Turks displaced the more tolerant Fatimid rulers of the region. This gave Urban a concrete grievance to rally support around.
• Responding to Byzantium: Byzantine Emperor Alexios I Komnenos had sent envoys requesting military aid against the Seljuk Turks, who had crushed the Byzantine army at the Battle of Manzikert (1071) and conquered much of Anatolia (modern-day Turkey). Urban saw an opportunity to both aid a fellow Christian ruler and extend papal influence, potentially even healing the 1054 schism on Rome's terms.
• Consolidating papal authority: Urban was locked in a power struggle with Holy Roman Emperor Henry IV (part of the broader Investiture Controversy over who could appoint church officials). A successful Crusade would dramatically boost the papacy's prestige and demonstrate the Pope's ability to mobilize all of Christendom.

Pope Urban II's promises:

Urban offered powerful spiritual incentives to those who "took up the cross":

• Remission of sins: Crusade participants would receive a plenary indulgence, meaning all penances owed for past sins would be forgiven.
• Spiritual reward for martyrdom: Those who died fighting would be considered martyrs for the faith, with the expectation of heavenly reward.

These promises were enormously persuasive in a society where fear of damnation and the burden of penance were very real parts of daily life.

The response:

The crowd at Clermont reportedly responded with shouts of "Deus vult!" ("God wills it!"), which became the Crusaders' rallying cry. Enthusiasm spread across Europe, drawing both nobility and common people from France, Germany, Italy, and beyond. The First Crusade launched in 1096, with armies marching overland to Constantinople before proceeding toward the Holy Land. Jerusalem fell to the Crusaders in 1099.

Religiously Sanctioned Warfare Concepts

Both Christianity and Islam developed frameworks for when warfare could be considered morally or spiritually justified. Understanding these concepts helps explain how leaders on both sides framed the Crusades.

Christianity and just war:

Saint Augustine of Hippo (354–430 CE) developed just war theory, building on earlier Roman ideas. His framework laid out criteria that a war had to meet to be considered morally acceptable:

1. Just cause: The war must address a genuine wrong, such as self-defense or protecting the innocent.
2. Right intention: The goal must be restoring peace and justice, not conquest or revenge.
3. Legitimate authority: Only proper governing authorities (not private individuals) could declare war.
4. Proportionality: The expected benefits must outweigh the expected destruction.
5. Last resort: All peaceful means of resolving the conflict must be exhausted first.

The Crusades were framed as an extension of this theory. Supporters argued they were a defensive war to protect Christian lands and pilgrims from aggression. They were also presented as a penitential act, meaning participation itself was a form of spiritual purification, reinforced by Urban's promises of sin remission. This was a significant development: it merged the idea of warfare with the idea of pilgrimage, creating the concept of the armed pilgrim.

Islam and jihad:

The concept of jihad (meaning "struggle" or "striving") in Islam has two dimensions:

• Greater jihad: The internal, spiritual struggle against one's own sins, temptations, and ego. This is considered the more important form.
• Lesser jihad: The external, physical struggle to defend the faith and protect the Muslim community (ummah).

Conditions for engaging in lesser jihad include self-defense when Muslim lands or people are attacked, defending the freedom to practice Islam when it is suppressed, and protecting the vulnerable (the poor, orphans, refugees). Muslim leaders like Saladin would later invoke these principles when rallying forces to recapture Crusader-held territories.

Comparing the two frameworks:

Both traditions permit warfare only under specific, limited circumstances and treat it as a last resort rather than a first option. Christian just war theory centers on just cause, right intention, and legitimate authority, while Islamic teachings on lesser jihad center on self-defense, religious freedom, and protection of the oppressed. In practice, leaders on both sides often stretched these frameworks to justify wars that didn't neatly fit the stated criteria. The gap between the theory and the reality of Crusade-era violence is something worth keeping in mind as you study this period.