The German Peasants' War (1524-1525) was a widespread popular revolt launched by peasants across the German-speaking lands of Central Europe, targeting the aristocracy. The revolt was influenced by the rise of Lutheranism during the Protestant Reformation, with Martin Luther's former professor Andreas Karlstadt promoting iconoclasm, democracy, and secularism. The first revolts broke out in southwestern Germany and in Alsace, and the revolts spread to other parts of Germany and Austria. Peasants and farmers, supported by Protestant clergy, took the lead of the uprising, but they lacked artillery, cavalry, and a command structure. In many battles, the peasants would turn and flee, only to be massacred by pursuing Imperial troops. Up to 100,000 of the 300,000 rebellious peasants were slaughtered by the forces of the Swabian League, which suffered minimal losses.