Medieval Roman Catholicism and the seeds of reform: Papal Monarchy, Sacramental Consolidation, Dissent, Crisis, and the Eve of Reformation, AD 1054–1516

Between the conventional East-West Schism of 1054 and the eve of Luther’s public indulgence controversy in 1517, Latin Christianity became more institutionally centralized, theologically systematized, sacramentally regulated, and socially pervasive than it had been in the first millennium. This chapter reconstructs that transformation without reducing the Middle Ages either to an age of unbroken corruption or to an undifferentiated golden age. It traces Gregorian reform, the Investiture Controversy, the growth of papal monarchy and canon law, crusading, the Fourth Crusade and sack of Constantinople, the formalization of the seven-sacrament system, transubstantiation and Eucharistic devotion, penitential theology, purgatory and indulgences, saints and Marian devotion, monastic and mendicant renewal, universities and scholasticism, inquisitorial structures, and late medieval popular piety. It then follows the reform currents associated with the Waldensians, John Wycliffe and the Lollards, Jan Hus and the Hussites, conciliarism, the Devotio Moderna, Renaissance humanism, printing, and Erasmus’s 1516 Greek New Testament. Particular care is taken to distinguish official doctrine from popular practice, genuine reform from later Protestant appropriation, and historical descent from retrospective claims of ancestry. The chapter argues that the Reformation did not erupt from a religious vacuum. Medieval Latin Christianity generated both the structures later challenged by Protestants and many of the intellectual, pastoral, textual, and institutional resources used to challenge them. A Sola Scriptura assessment affirms genuine medieval achievements while testing papal supremacy, sacerdotal mediation, sacramental claims, transubstantiation, purgatory, indulgences, invocation of saints, Marian devotion, coercive religion, and restrictions on preaching and Scripture by the apostolic Word.