The incessant conflict between the Catholics and Protestants allowed Germany no repose. A sincere toleration, such as existed during the reign of Maximilian I., established fraternal feelings between the contending parties. But it required ages of suffering and peculiar combination of circumstances, to lead the king and the nobles to a cordial consent to that toleration. But the bigotry of Rhodolph and the trickery of Matthias, had so exasperated the parties, and rendered them so suspicious of each other, that the emperor, even had he been so disposed, could not, but by very slow and gradual steps, have secured reconciliation. Rhodolph had put what was called the ban of the empire upon the Protestant city of Aix-la-Chapelle, removing the Protestants from the magistracy, and banishing their chiefs from the city. When Rhodolph was sinking into disgrace and had lost his power, the Protestants, being in the majority, took up arms, reflected their magistracy, and expelled the Jesuits from the city. The Catholics now appealed to Matthias, and he insanely revived the ban against the Protestants, and commissioned Albert, Archduke of Cologne, a bigoted Catholic, to march with an army to Aix-la-Chapelle and enforce its execution. Opposite Cologne, on the Rhine, the Protestants, in the days of bitter persecution, had established the town of Mulheim. Several of the neighboring Protestant princes defended with their arms the refugees who settled there from all parts of Germany. The town was strongly fortified, and here the Protestants, with arms in their hands, maintained perfect freedom of religious worship. The city grew rapidly and became one of the most important fortresses upon the river. The Catholics, jealous of its growing power, appealed to the emperor. He issued a decree ordering the Protestants to demolish every fortification of the place within thirty days; and to put up no more buildings whatever.