Beginning of the Protestant Reformation: After the Second Diet of Speyer bans Lutheranism, a group of rulers (German: Fürst) and independent cities protest the reinstatement of the Edict of Worms.

The Reformation, also known as the Protestant Reformation or the European Reformation, was a time of major theological movement in Western Christianity in 16th-century Europe that posed a religious and political challenge to the papacy and the authority of the Catholic Church. Towards the end of the Renaissance, the Reformation marked the beginning of Protestantism. It is considered one of the events that signified the end of the Middle Ages and the beginning of the early modern period in Europe.

The Diet of Speyer or the Diet of Spires was a Diet of the Holy Roman Empire held in 1529 in the Imperial City of Speyer. The Diet condemned the results of the Diet of Speyer of 1526 and prohibited future reformation. It resulted in the Protestation at Speyer.

Fürst is a German word for a ruler as well as a princely title. Fürsten were, starting in the Middle Ages, members of the highest nobility who ruled over states of the Holy Roman Empire and later its former territories, below the ruling Kaiser (emperor) or König (king).

In the Holy Roman Empire, the collective term free and imperial cities, briefly worded free imperial city, was used from the 15th century to denote a self-ruling city that had a certain amount of autonomy and was represented in the Imperial Diet.

On 19 April 1529, six princes and representatives of 14 Imperial Free Cities petitioned the Imperial Diet at Speyer against an imperial ban of Martin Luther, as well as the proscription of his works and teachings, and called for the unhindered spread of the evangelical faith.