The further progress of Gustavus Adolphus in the ecclesiastical territories agreed with this brilliant commencement. Schweinfurt, and soon afterward Würtzburg, abandoned by their Imperial garrisons, surrendered; but Marienberg he was obliged to carry by storm. In this place, which was believed to be impregnable, the enemy had collected a large store of provisions and ammunition, all of which fell into the hands of the Swedes. The king found a valuable prize in the library of the Jesuits, which he sent to Upsal, while his soldiers found a still more agreeable one in the prelate's well-filled cellars; his treasures the bishop had in good time removed. The whole bishopric followed the example of the capital, and submitted to the Swedes. The king compelled all the bishop's subjects to swear allegiance to himself; and, in the absence of the lawful sovereign, appointed a regency, one-half of whose members were Protestants. In every Roman Catholic town which Gustavus took, he opened the churches to the Protestant people, but without retaliating on the Papists the cruelties which they had practised on the former. On such only as sword in hand refused to submit, were the fearful rights of war enforced; and for the occasional acts of violence committed by a few of the more lawless soldiers, in the blind rage of the first attack, their humane leader is not justly responsible. Those who were peaceably disposed, or defenceless, were treated with mildness. It was a sacred principle of Gustavus to spare the blood of his enemies, as well as that of his own troops.