The Catholic Reaction was now in full swing. With the determination of Catholicism to regain her ancient dominion came the Thirty Years War, the last and cruellest of the religious wars, which deprived Germany of, some say, half her population, and turned a comparatively rich and prosperous country into a barren desert. The violence of Duke Maximilian of Bavaria towards the town of Donauwörth (1607), "which had been put under Ban of the Empire for some fault on the part of the populace against a flaring Mass-procession which had no business to be there," filled the free-towns and Protestant communities with dark forebodings of approaching disturbance. An Evangelical League, "The Union," was formed by the towns and princes for the purposes of self-defence against any attacks on religious freedom. Nuremberg joined it in 1610. This step was, of course, distasteful to the Emperor, but Nuremberg was left no choice in the matter. For the bishops of Bamberg and Eichstätt had forced the Nuremberg Evangelical subjects, living in their dioceses, to revert to the old religion. The Catholic communities formed a counter-league. Only a signal was wanted to make the opposing parties draw swords; and in 1618 the Bohemian resistance to the suppression of the Evangelical religion gave the signal for that bloody war, in which Nuremberg was to endure her full share of suffering. But, first, for a long time she endeavoured to pursue her old policy of neutrality, keeping peace with both parties and remaining subject to the Emperor. Meantime, as one after another of the Catholic generals passed through, men were quartered on Nuremberg in ceaseless relays, and she was bled of money and provisions. The treasury was depleted; trade disorganised; and the peasantry suffered cruelly.