structural:reformatting
Princely Reformation in Germany

The Grand Master of the Teutonic Knights Albert of Brandenburg-Ansbach (r. 1510–1525) was the first prince to formally abandon Catholicism. The Teutonic Order held Royal Prussia in fief of Poland. After defeats in a war against Poland and Lithuania demoralised the Knights, Albert transformed the region into the hereditary Duchy of Prussia in April 1525. As the secularisation of Prussia represented an open rebellion against Catholicism, it was followed by the establishment of the first Evangelical state church. In August, Albert's brothers, Casimir (r. 1515–1527) and George (r. 1536–1543) instructed the priests in Brandenburg-Kulmbach and Brandenburg-Ansbach to pray the doctrine of justification by faith alone. The Reformation was officially introduced in Electoral Saxony under John the Constant (r. 1525–1532) on Christmas Day 1525. Electoral Saxony's conversion facilitated the adoption of the Reformation in smaller German states, such as Mansfeld and Hessen. Philip of Hessen founded the first Evangelical university at his capital Marburg in 1527.

At the Diet of Speyer in 1526, the German princes agreed that they would "live, govern, and act in such a way as everyone trusted to justify before God and the Imperial Majesty". In practice, they sanctioned the principle cuius regio, eius religio ('whose realm, their religion'), acknowledging the princes' right to determine their subjects' religious affiliation. Fully occupied with the War of the League of Cognac against France and its Italian allies, Emperor Charles had appointed his brother Ferdinand I, Archduke of Austria (r. 1521–1564) to represent him in Germany. They both opposed the compromise, but Ferdinand was brought into succession struggles in Bohemia and Hungary after their brother-in-law King Louis died in the Battle of Mohács. In 1527, Charles's mutinous troops sacked Rome and took Pope Clement VII (r. 1523–1534) under custody. Luther stated that "Christ reigns in such a way that the emperor who persecutes Luther for the pope is forced to destroy the pope for Luther".

After his experiences with radical communities, Luther no more wrote of the congregations' right to elect their ministers (or pastors). Instead, he expected that princes acting as "emergency bishops" would prevent the disintegration of the Church. Close cooperation between clerics and princely officials at church visitations paved the way for the establishment of the new church system. In Electoral Saxony, princely decrees enacted the Evangelical ideas. Liturgy was simplified, the church courts' jurisdiction over secular cases was abolished, and state authorities took control of church property. The Evangelical equivalent to bishop was created with the appointment of a former Catholic priest Johannes Bugenhagen (d. 1558) as superintendent in 1533. The church visitations convinced Luther that the villagers' knowledge of the Christian faith was imperfect. To deal with the situation, he completed two cathecisms —the Large Catechism for the education of priests, and the Small Catechism for children. Records from Brandenburg-Ansbach indicates that Evangelical pastors often attacked traditional communal activities such as church fairs and spinning bees for debauchery.

"In matters concerning God's honor and our soul's salvation everyone must stand before God and answer by himself, nobody can excuse himself in that place by the actions of decisions of others whether they be a minority or majority."

Five imperial princes and representatives of fourteen imperial cities, Protestation at Speyer (1529)

Taking advantage of Emperor Charles' victories in Italy, Ferdinand I achieved the reinforcement of the imperial ban against Luther at the Diet of Speyer in 1529. In response, five imperial princes and fourteen imperial cities presented a formal protestatio. They were mocked as "Protestants", and this appellation would be quickly applied to all followers of the new theologies. To promote Protestant unity, Philip the Magnanimous organised a colloquy (or theological debate) between Luther, Melanchton, Zwingli and Oecolampadius at Marburg early in October 1529, but they could not coin a common formula on the Eucharist. During the discussion, Luther remarked that "Our spirit has nothing in common with your spirit", expressing the rift between the two mainstream versions of the Reformation. Zwingli's followers started to call themselves the " Reformed ", as they regarded themselves as the true reformers.