At any other time the Lutheran matter would probably have ended there. But 1521 was no ordinary moment in the empire’s history. When he died in 1519, Maximilian had not succeeded in having his grandson and heir, Charles, designated his successor. King of Castile and Aragon since 1516 and suzerain also over Habsburg lands in the Netherlands, Naples, and central and eastern Europe—not to mention the Spanish possessions in the New World—Charles posed a formidable problem for the electors. Should they choose a man whose vast resources might well empower him to centralize authority in the empire when this would limit their hard-won autonomy? Should they elect a prince whose international commitments would entangle Germany in European conflicts? The only other viable candidate was the king of France, Francis I, who recognized in the rapidly growing Habsburg ascendancy a serious threat to his own power. But, though Francis made tempting promises, the electors, in the end, opted for Charles—not, however, without drawing from him a 36-point “electoral capitulation” in which he swore to uphold the estates’ prerogatives. In making this choice, the electors strove to secure their own privileges, but the German public tended to see in the new monarch a fulfillment of national aspirations—mistakenly, as it turned out, but giving rise, at the time, to patriotic expressions of hopes for a brighter future. Coinciding with these events in the political realm and gaining resonance from them, the Lutheran matter was inevitably drawn into the political vortex, thereby acquiring the features of a national cause.

Delayed by disturbances in his Spanish domains, Charles reached Germany late in 1520. He was crowned king in Aachen, assuming at the same time the title of Roman emperor-elect. He then proceeded to Worms, where he was to meet with the German estates in early 1521. By then no other issue counted as much on the agenda as the Lutheran affair. Acting out of what appears to be a blend of conviction and political expediency, the estates’ leaders, prompted by Frederick the Wise, the elector of Saxony, demanded that the Diet of Worms reopen Luther’s case by allowing the excommunicated friar to speak before the estates. Unable to resist, the emperor issued a safe-conduct, and Luther traveled to Worms, treated on his way to such extravagant public acclaim that he must have felt like a national hero. On April 17 and 18 he stood before the emperor and representatives of the estates. He refused to revoke his views on justification and other points of theology, reiterated his denial of ultimate authority to pope and church councils, and—when pressed—asserted the principle of individual responsibility in matters of faith:

As long as my conscience is held captive by the words of God, I cannot and will not revoke anything, for it is dangerous, and a great peril to salvation, to act against conscience. God help me. Amen.

These words, and all else that transpired, were broadcast to the country in scores of pamphlets in which Luther was cast in the role of the man sent by God to cleanse the German church. While an imperial edict condemned his teachings and placed him and his adherents under the ban, Luther himself was offered a refuge in the Wartburg, Frederick the Wise’s castle in the Thuringian Forest. There, fretting over his enforced absence from events, he turned to the translation of the New Testament, while the movement, of which he was now the acknowledged head, gained momentum.

Analysis of what happened at Worms reveals the first signs of what was to become a fateful split in the self-perception of this movement. The estates saw it as a means of promoting ecclesiastical reform; on questions of faith, they were willing to compromise. Luther, on the contrary, tolerated no distinction between points of faith and aspects of church practice, and on his understanding of the former he stood rock-solid. He and his political patrons were thus pursuing different ends; for the present, however, his support in official circles was, for whatever reason, substantial.

Luther’s hold on the general public was even more impressive than his hold on the political leadership. Historians are not unanimous in explaining how this friar from the German east, utterly obscure only five years earlier, could have gained such a following by 1521 that few governments would enforce the ban against him, knowing that they would face strong resistance if they tried to do so. It is not clear whether the general population, still largely illiterate, understood the doctrine of faith alone well enough to make it the object of informed choice. More likely, the German populace took Luther not as the preeminently religious prophet he was but saw in him their best hope of achieving an amelioration of the many troubles vexing them in their respective stations, not only in religion but also, and perhaps mainly, in their social condition. Against these conditions, the products of deeply rooted legal and institutional structures, Luther—or so people seem to have understood him—raised the standard of Evangelical morality: all things were to be judged by scripture and God’s law.

Scholars have often pointed out that this view is less attributable to the Wittenberg reformer than to another theologian and preacher then beginning to be active in the Swiss city of Zürich, Huldrych Zwingli. Luther explicitly rejected the use of the—to him purely spiritual—New Testament as a norm for social reform. But Zwingli affirmed it. On the other hand, Luther’s vehemence and forceful rhetoric were so compelling that, rightly or wrongly, his name came to be fused with the general hope of improvement in human affairs. His partisans, proficient in their use of the media of print and woodcut illustration, helped shape this conviction by furnishing propaganda for a strong popular drive toward Lutheranism. This drive from below, further nourished by traditional anticlerical sentiments, was met from above by the eagerness of territorial and urban governments to utilize Lutheran ideas as legitimation for the extension of political control over the church. Thus, by the mid-1520s a number of German cities and states had formally turned Lutheran, meaning that they had severed their legal and administrative ties to Rome and its prelates and were building new ecclesiastical institutions and framing new doctrines.