In a sense, the Reformation was a protest against the secular values of the Renaissance. No Italian despots better represented the profligacy, the materialism, and the intellectual hedonism that accompanied these values than did the three Renaissance popes, Alexander VI, Julius II, and Leo X. Among those precursors of the reformers who were conscious of the betrayal of Christian ideals were figures so diverse as the Ferraran monk Savonarola, the Spanish statesman Cardinal Jiménez, and the humanist scholar Erasmus.

The corruption of the religious orders and the cynical abuse of the fiscal machinery of the church provoked a movement that at first demanded reform from within and ultimately chose the path of separation. When the Augustinian monk Martin Luther protested against the sale of indulgences in 1517, he found himself obliged to extend his doctrinal arguments until his stand led him to deny the authority of the pope. In the past, as in the controversies between pope and emperor, such challenges had resulted in mere temporary disunity. In the age of nation-states, the political implications of the dispute resulted in the irreparable fragmentation of clerical authority.

Luther had chosen to attack a lucrative source of papal revenue, and his intractable spirit obliged Leo X to excommunicate him. The problem became of as much concern to the emperor as it was to the pope, for Luther’s eloquent writings evoked a wave of enthusiasm throughout Germany. The reformer was by instinct a social conservative and supported existing secular authority against the upthrust of the lower orders. Although the Diet of Worms accepted the excommunication in 1521, Luther found protection among the princes. In 1529 the rulers of electoral Saxony, Brandenburg, Hessen, Lüneberg, and Anhalt signed the “protest” against an attempt to enforce obedience. By this time, Charles V had resolved to suppress Protestantism and to abandon conciliation. In 1527 his mutinous troops had sacked Rome and secured the person of Pope Clement VII, who had deserted the imperial cause in favour of Francis I after the latter’s defeat at the Battle of Pavia. The sack of Rome proved a turning point both for the emperor and the humanist movement that he had patronized. The humanist scholars were dispersed, and the initiative for reform then lay in the hands of the more violent and uncompromising party. Charles V himself experienced a revulsion of conscience that placed him at the head of the Roman Catholic reaction. The empire he ruled in name was now divided into hostile camps. The Catholic princes of Germany had discussed measures for joint action at Regensburg in 1524; in 1530 the Protestants formed a defensive league at Schmalkalden. Reconciliation was attempted in 1541 and 1548, but the German rift could no longer be healed.

Lutheranism laid its emphasis doctrinally on justification by faith and politically on the God-given powers of the secular ruler. Other Protestants reached different conclusions and diverged widely from one another in their interpretation of the sacraments. In Geneva, Calvinism enforced a stern moral code and preached the mystery of grace with predestinarian conviction. It proclaimed the separation of church and state, but in practice its organization tended to produce a type of theocracy. Huldrych Zwingli and Heinrich Bullinger in Zürich taught a theology not unlike Calvin’s but preferred to see government in terms of the godly magistrate. On the left wing of these movements were the Anabaptists, whose pacifism and mystic detachment were paradoxically associated with violent upheavals.

Lutheranism established itself in northern Germany and Scandinavia and for a time exercised a wide influence both in eastern Europe and in the west. Where it was not officially adopted by the ruling prince, however, the more militant Calvinist faith tended to take its place. Calvinism spread northward from the upper Rhine and established itself firmly in Scotland and in southern and western France. Friction between Rome and nationalist tendencies within the Catholic church facilitated the spread of Protestantism. In France the Gallican church was traditionally nationalist and antipapal in outlook, while in England the Reformation in its early stages took the form of the preservation of Catholic doctrine and the denial of papal jurisdiction. After periods of Calvinist and then of Roman Catholic reaction, the Church of England achieved a measure of stability with the Elizabethan religious settlement.

In the years between the papal confirmation of the Jesuit order in 1540 and the formal dissolution of the Council of Trent in 1563, the Roman Catholic church responded to the Protestant challenge by purging itself of the abuses and ambiguities that had opened the way to revolt. Thus prepared, the Counter-Reformation embarked upon recovery of the schismatic branches of Western Christianity. Foremost in this crusade were the Jesuits, established as a well-educated and disciplined arm of the papacy by Ignatius Loyola. Their work was made easier by the Council of Trent, which did not, like earlier councils, result in the diminution of papal authority. The council condemned such abuses as pluralism, affirmed the traditional practice in questions of clerical marriage and the use of the Bible, and clarified doctrine on issues such as the nature of the Eucharist, divine grace, and justification by faith. The church thus made it clear that it was not prepared to compromise; and, with the aid of the Inquisition and the material resources of the Habsburgs, it set out to reestablish its universal authority. It was of vital importance to this task that the popes of the Counter-Reformation were men of sincere conviction and initiative who skillfully employed diplomacy, persuasion, and force against heresy. In Italy, Spain, Bavaria, Austria, Bohemia, Poland, and the southern Netherlands (the future Belgium), Protestant influence was destroyed.