Ozment, Steven E. The Age of Reform: 1250-1550 : An Intellectual and Religious History of Late Medieval and Reformation Europe. New Haven, Conn. ; London: Yale University Press, 1980. Kindle Electronic Edition.
Chapter 9, “The Swiss Reformation” pp. 318-339. Part 3, “The Working Out of Zwinglianism” pp. 332-339.
“Between 1525 and 1530 Zwinglian ideas and practices spread rapidly throughout Switzerland and South Germany” (Ozment 1980, 332). The Zwinglians made more substantial breaks with existing practice than the Lutherans did. The Catholics held a conference in Baden in May, 1526. Zwingli was represented by Johannes Oecolampadius, who was defeated in debate with John Eck (Ozment 1980, 334). The Zwinglians held their own conference in January, 1528, in Bern. The city became Protestant in 1528, setting a tone for later growth of Protestantism. Because of the diversion between Luther and Zwingli, Philip of Hesse “invited the two Protestant leaders to his castle in Marburg for a special religious colloquy between October 1 and 4, 1529” (Ozment 1980, 334). Each party was disinclined to agree with the other. While Luther confessed a real, physical presence of Christ in communion, Zwingli considered the elements as symbols only. Luther developed his view of the communicatio idiomatum, while Zwingli considered that “the physical could not nourish the spiritual” (Ozment 1980, 336). The Marburg Colloquy did not result in agreement on communion. From 1530 on the Zwinglian and Lutheran churches were at odds with one another. In rather short order the various groups were entrenched and worked out arrangements by which Catholic and Protestant would not proselytize in other territories. There were military clashes following that time, including one in 1531 resulting in Zwingli’s death.