Forward, Christian Soldiers: Zwingli's Wars, the Marburg Colloquy, and Death at Kappel, 1524–1531

Durant on the Swiss Reformation turning to arms: the Catholic League of Five Cantons, the iconoclasm of Basel and Oecolampadius, the bloodless First Peace of Kappel, the failed Marburg meeting with Luther over the Eucharist, Zwingli's vision of a heaven with pagan sages, his death at the second Kappel, and Bullinger's patient legacy.

Battle of KappelMarburg ColloquyZwingli and Luther

~11 min read · Updated Oct 31, 2026

A Confederation Torn

The Reformation had torn the fabric of the Swiss Confederation and seemed to threaten its dissolution. Bern, Basel, Schaffhausen, Appenzell and the Grisons favored Zurich, but the other cantons had turned hostile to it. Five cantons, Lucerne, Uri, Schwyz, Unterwalden and Zug, formed a Catholic league to crush the followers of Hus, Luther and Zwingli (1524). Archduke Ferdinand of Austria called on all Catholic powers to act together against the Protestants and, hoping to restore Habsburg rule in Switzerland, promised the league his help. On July 16 all the cantons but Schaffhausen and Appenzell agreed not to admit Zurich's delegates to future diets of the Confederation. Zurich and Zwingli answered by sending preachers to spread the Reformation in Thurgau. One of them was arrested; his companions freed him and, at the head of an unruly crowd, plundered and burned a monastery and destroyed images in several churches (July 1524). Three ringleaders were executed, and the fighting spirit of both camps was roused. Erasmus, watching in fear from Basel, saw devout Christians at the urging of their preachers come out of church "with faces flushed with anger and hatred, like men possessed and soldiers ready for a terrible attack at their commanders' word." Six cantons threatened to leave the Confederation unless Zurich was chastened.

Zwingli, who had taken command of the fighting men, proposed that the government of Zurich enlarge its troops and equipment, ally itself with France, kindle an uprising in the Tyrol behind Ferdinand's lines, and promise Thurgau and St. Gallen that the monasteries' property would go to them in return for supporting Zurich. To reach a compromise with the Catholic league he then proposed that it hand over the famous abbey of St. Gallen to Zurich, break its alliance with Austria, and surrender Thomas Murner, the satirist of Lucerne who had showered the reformers with abuse. When the league met these terms with mockery, Zurich ordered its deputies in St. Gallen to occupy the abbey, and they did so (January 28, 1529). Events at Basel in February raised the tension further.

Basel and the Breaking of Images

The Protestants of Basel, the "Athens of Switzerland," were led by Johannes Hussgen, who had changed his name to Oecolampadius, "house lamp." At twelve he wrote Latin verse; soon after he mastered Greek, and after Reuchlin he became the foremost teacher of Hebrew. As pastor of St. Martin's and professor of theology at the university, he called himself a moral and religious reformer and declared he would accept no compromise in matters of faith. In 1521 he criticized confession, transubstantiation and the cult of the Virgin. In 1523 Luther spoke well of him. In 1525 he accepted Zwingli's program, including the persecution of Anabaptists. But he rejected predestination, saying, "our salvation is from God, our damnation in our own hands." When the Basel council, now controlled by Protestants, proclaimed freedom of worship (1528), he protested and demanded that the Mass be banned. On February 8, 1529, eight hundred men gathered in the Franciscan church and asked the council to ban the Mass, dismiss all Catholics from public office and draw up a more democratic constitution. The council debated. The next day, while it was still considering the demands, the petitioners gathered in the marketplace with axes and hammers, and at noon rushed into the churches and destroyed every image in their path. Erasmus described it in a letter to Pirckheimer:

Smiths and laborers threw the pictures out of the churches and heaped many insults on the figures of the saints and even the crucified Christ, and strangely, the saints worked no miracle. In churches, aisles, porches and monasteries not a statue was left whole. Frescoes were wiped out with whitewash. Whatever could burn was thrown on the fire, the rest was broken to pieces. Nothing precious or beloved escaped their hands.

The council finally banned the Mass in the canton of Basel. Erasmus, Beatus Rhenanus and almost all the professors left the University of Basel. Oecolampadius lived two years after this victory and died shortly after Zwingli.

The First War of Kappel

In May 1529 a Zurich Protestant who had come to Schwyz to preach was burned. The Zurich council, at Zwingli's urging, declared war on the league of Catholic cantons. Zwingli himself drew up the plan of campaign and personally took command of Zurich's army. At Kappel, ten miles south of Zurich, Landammann Aebli of Glarus asked Zwingli to halt his men's advance for an hour while he negotiated with the Catholic league. Suspecting a trick, Zwingli ordered an advance; but his Bernese allies and his own soldiers, who were ready to befriend the enemy soldiers across lines of creed and canton, refused to obey. Truce negotiations lasted sixteen days, and in the end the Swiss love of peace prevailed over hostility and spite, and the First Peace of Kappel was signed on June 24, 1529. It was a victory for Zwingli: the Catholic cantons undertook to pay Zurich an indemnity and give up their military alliance with Austria; both sides promised not to attack each other over religion; and in the "common lands" ruled by two or more cantons the people could decide their religious order by majority vote. Yet Zwingli was not much pleased, for his demand for freedom of religious preaching in the Catholic cantons was refused. He predicted a short life for the treaty.

The Failure at Marburg

The peace of Kappel held for twenty-eight months. In that time attempts were made to unite the Swiss Protestant cantons with Germany. Charles V had now set aside his quarrel with Clement VII, and this made cooperation of pope and emperor against the Protestants easier. But the Protestants too were now a strong political power. Half of the German people followed Luther, and the people of many German cities, such as Ulm, Augsburg, Mainz, Frankfurt and Strasbourg, favored Zwingli. Many Swiss towns, unlike the countryside, had also embraced Protestantism. Plainly the threats of pope and emperor forced the Protestants to unite to survive. The only obstacle was the theological differences among the Protestant sects.

Philip of Hesse took the lead, arranging for Luther, Melanchthon and other German Protestants to meet Zwingli, Oecolampadius and other Swiss Protestants in his castle at Marburg. On September 29, 1529, the leaders of the Protestant parties met. Zwingli, to come closer to the German Protestants, made large concessions: he removed from Luther's mind the notion that he denied Christ's divinity, accepted the Nicene Creed, and affirmed original sin. But he did not give up his view that the Lord's Supper is a memorial of Christ's sacrifice and not a miracle. Luther wrote in chalk on the table, "This is my body." These words were attributed to Christ, and Luther would accept no reading but the literal. The Protestant leaders agreed on fourteen articles, but split over the meaning and standing of the sacrament (October 3). Luther rejected Zwingli's offered hand, saying, "Your spirit is not our spirit." He drew up a confession of seventeen articles, one of which affirmed transubstantiation (the book's term), and warned the princes who favored him against allying with those who would not accept all of them. Melanchthon, backing his leader, summed up the conference: "We told Zwingli's followers how their consciences allow them to call us brothers while they hold our beliefs mistaken." This phrase shows the temper of the age. In 1532 Luther warned Albert, duke of Prussia, not to let any follower of Zwingli enter his land, on pain of eternal damnation. To expect Luther to give up medieval beliefs and quickly accept the modern was to expect too much. The medieval faith so filled his mind that he thought if one article of his creed shook, his whole world of thought would collapse and the meaning of life vanish. Luther was the most medieval of modern men.

Heaven for the Wise

Zwingli returned to Zurich, whose citizens were now tired of his rule. Strict laws limiting personal spending had worn them out; religious quarrels had halted trade between the cantons; the craftsmen resented their small voice in government; and Zwingli's sermons, now mixed with politics, no longer moved hearts as before. Seeing his influence decline, he asked the council to let him leave Zurich and take a parish outside the city, but the council refused.

Thereafter he busied himself with writing. In 1530 he sent his Exposition of the Faith to Charles V, who never acknowledged it. The next year he sent a brief, plain statement of the Christian faith to Francis I. In it Zwingli, like Erasmus, claimed that in paradise Christians would find many virtuous Jews and pagans, and that Hercules, Theseus, Socrates, Aristides, Numa Pompilius, Camillus, the Catos and the Scipios would stand before God beside Adam, Abraham, Isaac, Moses and Isaiah. "In short," he wrote, "from the beginning to the end of the world there is no good, pure-minded and honest man who has entered life and whom one will not see in God's presence. What scene more pleasing, moving and lofty can be imagined?" Luther was so incensed by this that he accused Zwingli of unbelief, and Bishop Bossuet, who opposed Luther, agreed with him that Zwingli was an unbeliever.

Kappel, 1531

On May 15, 1531, an assembly of delegates of Zurich and its allies resolved to force the Catholic cantons to guarantee freedom of religious preaching in their lands. When the cantons refused, Zwingli proposed that Zurich and its allies go to war, but Zurich's allies preferred an economic blockade. The Catholic cantons, cut off from imports, declared war on the Protestant ones. Once again the armies lined up, with Zwingli in command, setting an example to his men. Zwingli's force of 1,500 fighting men again met a Catholic force of 8,000 at Kappel (October 11, 1531), and a bloody battle began. The Catholics beat the Protestants, and Zwingli, aged forty-seven, was among about five hundred men of Zurich killed. The Catholics desecrated his body (the book's account is gruesome and omitted here). When Luther heard of Zwingli's death he called it God's punishment of an unbeliever and "our victory." He is said to have remarked, "I wish with all my heart that Zwingli be saved, but I foresee the opposite for him, for Christ said that those who deny him will be condemned."

Bullinger and a Divided Switzerland

At Zurich Heinrich Bullinger succeeded Zwingli, and at Basel Oswald Myconius led the Protestants after Oecolampadius's death. Bullinger withdrew from politics and devoted himself to supervising the city's schools, settling Protestant refugees and aiding the needy regardless of belief. Although he approved the execution of Servetus, he more or less believed in freedom for all religions. With Myconius and Leo Jud, Bullinger drew up the First Helvetic Confession (1536), which for a generation served as the official statement of Zwingli's views, and signed with Calvin the Consensus Tigurinus (1549), which joined the Protestants of Zurich and Geneva in a single reformed church.

Despite these defensive efforts, Catholicism, through the victory at Kappel, regained many lost lands in Switzerland. Schools of theology rise or fall, throughout history, with the victory or defeat of rival parties. Seven cantons, Lucerne, Uri, Schwyz, Zug, Unterwalden, Fribourg and Solothurn, became Catholic; four, Zurich, Basel, Bern and Schaffhausen, remained Protestant. The other cantons kept their neutrality between the two blocs. Valentin Tschudi, Zwingli's successor at Glarus, celebrated Mass for the Catholics in the morning and in the evening preached the Gospel to the Protestants. He urged Catholics and Protestants to live together, and both accepted him with tolerance. He wrote the history of his time with such impartiality that his religious leanings cannot be told from it. Even in those days there were Christians.

Written & researched by Dr. Shahin Siami

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