1523 marked the start of the religious wars between Catholics and Protestants, with the majority of the town's residents converting to the new break-away faith - Bunzlau became an important center of the Protestant Reformation.
In 1642, during the Thirty Years' War, Bunzlau experienced another hostile event, this time a pillaging by Swedish forces under General Lennart Torstenson, which reduced the castle, church, and much of the housing to ruins.