After an easy and unexpected conquest, the quick soldier soon saw that the Swedish lion had swallowed more than his stomach could carry. After the return of Yan Kazimir he lost hope of retaining the Commonwealth; but while making a mental abdication of the whole, he wished at least to retain the greater part of his conquest, and above all Royal Prussia,—a province fruitful, dotted with large towns, wealthy, and adjoining his own Pomerania. But as that province was first to defend itself, so did it continue faithful to its lord and the Commonwealth. The return of Yan Kazimir, and the war begun by the confederation of Tyshovtsi might revive the courage of Prussia, confirm it in loyalty, give it will for endurance; therefore Karl Gustav determined to crush the uprising, and to wipe out Kazimir’s forces so as to take from Prussians the hope of resistance. He had to do this for the sake of the elector, who was ever ready to side with the stronger. The King of Sweden knew him thoroughly, and doubted not for a moment that if the fortune of Yan Kazimir should preponderate, the elector would be on his side again. When, therefore, the siege of Marienburg advanced slowly,—for the more it was attacked the more stubbornly did Pan Weiher defend it,—Karl Gustav marched to the Commonwealth, so as to reach Yan Kazimir again, even in the remotest corner of the land. And since with him deed followed decision as swiftly as thunder follows lightning, he raised his army disposed in towns; and before any one in the Commonwealth had looked around, before the news of his march had spread, he had passed Warsaw and had rushed into the greatest blaze of conflagration. Driven by anger, revenge, and bitterness, he moved on like a storm. Behind him ten thousand horse trampled the fields, which were still covered with snow; and taking the infantry from the garrisons, he went on, like a whirlwind, toward the far south of the Commonwealth. On the road he burned and pursued. He was not now that recent Karl Gustav, the kindly, affable, and joyous lord, clapping his hands at Polish cavalry, winking at feasts, and praising the soldiers. Now, wherever he showed himself the blood of peasants and nobles flowed in a torrent. On the road he annihilated “parties,” hanged prisoners, spared no man. But as when, in the thick of the pine-woods, a mighty bear rushes forward with heavy body crushing branches and brush on the way, while wolves follow after, and not daring to block his path, pursue, press nearer and nearer behind, so did those “parties” pursuing the armies of Karl join in throngs denser and denser, and follow the Swedes as a shadow a man, and still more enduringly than a shadow, for they followed in the day and the night, in fair and foul weather; before him too bridges were ruined, provisions destroyed, so that he had to march as in a desert, without a place for his head or anything with which to give strength to his body when hungry.