Christianity and the Rise of Islam (7th–9th Centuries)

In the early seventh century, Christian majorities or strong pluralities still framed the Levant, Egypt, and North Africa inside late antique Roman–Byzantine and Sasanian worlds. Within a century, Islamic rule stretched from Spain’s edges to the Iranian plateau. Churches did not vanish overnight. Patriarchs negotiated, monks wrote apologies and polemics, farmers paid new taxes, and … Read More

The Enlightenment and Christianity: Reason, Churches, and the Limits of “Secular Age” Stories

Schoolbook history often stages the eighteenth century as a duel: philosophers of reason versus churches of superstition. That duel happened in pamphlets. It did not describe most of Europe’s Sundays. The Enlightenment was a family of arguments about authority, evidence, law, and improvement. Christianity was not a single opponent sitting still. State churches, dissenting academies, … Read More

Conversion of the Slavs: Cyril, Methodius, and Byzantium

When Slavic-speaking peoples entered the Christian story in force, they did not walk a single aisle toward a single altar. Some looked to Rome and Latin bishops; some to Constantinople and Greek missionaries; many lived for generations in zones where both missions competed. The brothers Constantine (later Cyril) and Methodius, sent from Byzantium to Great … Read More

Armenia and Ethiopia: Early Christian Kingdoms Outside the Empire

Constantine’s conversion gets the textbooks’ spotlight, but Armenia and Ethiopia tell a different origin story: Christian kingdoms that took shape outside the Roman imperial church’s direct command. Traditional dates place Armenia’s royal conversion under Tiridates III with Gregory the Illuminator in the early fourth century—often claimed as the first Christian state. Aksumite Ethiopia under Ezana … Read More

The Photian Schism and Ninth-Century East–West Conflict

A century and a half before the mutual excommunications of 1054, Rome and Constantinople already practiced the choreography of rupture: rival patriarchal claims, missionary turf wars, theological dossiers on the Filioque, and councils that condemned each other’s champions. The Photian Schism—named for Patriarch Photius of Constantinople—erupted in the 860s, healed imperfectly, flared again, and left … Read More

Gregorian Reform: What Did It Change in Medieval Christianity?

In the mid-eleventh century, a cluster of popes, cardinals, monks, and bishops set out to purify the Latin Church. They attacked the buying of holy offices, insisted that priests live as a distinct celibate order, and fought to free episcopal appointments from kings and local lords. Historians call this movement the Gregorian Reform—named for Pope … Read More

Cathars, Waldensians, and Medieval Dissent: Two Paths of Challenge

Twelfth- and thirteenth-century Latin Europe was not a monolith of obedient parishioners. Alongside saints, crusaders, and scholastic masters stood men and women who refused the church’s wealth, hierarchy, or metaphysics. Two names dominate textbooks of medieval dissent: Cathars and Waldensians. They are often paired because both were hunted, both preached outside official pulpits, and both … Read More

The Medieval Inquisition: Origins, Procedures, and Limits

Few institutions in Christian history are as myth-laden as the Inquisition. Popular imagination blends papal inquisitors, Spanish autos-da-fé, secret torture chambers, and an all-seeing medieval police state into one dark brand. Historians insist on distinctions. The medieval (or papal) Inquisition of the thirteenth and fourteenth centuries was not the Spanish Inquisition of the late fifteenth … Read More

Black Death and Late Medieval Christian Piety: Plague, Fear, and Faith

Between 1347 and 1351, bubonic and related plague forms tore through Europe and the wider Mediterranean world, killing a share of the population so large that exact percentages are still argued—often estimated around one-third in hard-hit regions, with local highs far worse. For Christians, the Black Death was not only a medical catastrophe. It was … Read More