§ 4. Tilly's advance and retreat.
Ferdinand had despised the danger from Gustavus. "We have got a new little enemy," he said, laughing, when he heard of the disembarkation of the Swedes. Tilly knew better. He pressed rapidly forward, hoping to thrust himself between Gustavus in Pomerania and his lieutenant, Horn, in Mecklenburg. If he succeeded, the invading army would be cut in two, and liable to be defeated in detail. Success at first attended his effort. On March 29, whilst the princes were debating at Leipzig, he took New Brandenburg, cutting down the whole Swedish garrison of 2,000 men. But Gustavus was too rapid for him. Uniting his forces with those of Horn, he presented a bold front to the enemy. Tilly was driven back upon the Elbe. The remaining fortresses on the Baltic, and the important post of Frankfort on the Oder, garrisoned with eight imperialist regiments, fell into the power of the conqueror.
§ 5. Magdeburg.
A greater and more important city than Frankfort was at stake. The citizens of Magdeburg had raised the standard of independence without waiting for leave from John George of Saxony. Gustavus had sent a Swedish officer to conduct their defence. But without the support of the Electors of Saxony and Brandenburg, he durst not bring his army to their assistance.
§ 6. Treaty of Cherasco.
The imperialists were gathering thickly round Magdeburg. On April 26 a treaty was signed at Cherasco, between France and the Empire, which restored peace in Italy, and set free the Emperor's troops beyond the Alps for service in Germany. If Tilly saw matters still in a gloomy light, his fiery lieutenant, Pappenheim, thought there was no reason to despair. "This summer," he wrote, "we can sweep our enemies before us. God give us grace thereto."
§ 7. Convention with the Elector of Brandenburg.
As the siege went on, Gustavus, writing under his enforced inaction, pleaded hard with the two Electors. From the Elector of Brandenburg he demanded the right to occupy the two fortresses of Küstrin and Spandau. Hopes were held out to him of the surrender of Küstrin, but he was assured that Spandau should never be his. Accompanied by a picked body of troops, he marched straight upon Berlin. On May 13, outside the city gates, he held a long conference with his brother-in-law, the Elector. He argued in vain. To one of the Dukes of Mecklenburg, who had accompanied him, he spoke in bitter words. "I am marching," he said, "upon Magdeburg, to deliver the city. If no one will assist me, I will retreat at once. I will offer peace to the Emperor, and go home to Stockholm. I know that the Emperor will agree to my terms. But you Protestants will have to answer at the day of judgment that you would do nothing for the cause of God. In this world, too, you will be punished. Magdeburg will be taken, and, if I retire, you will have to look to yourselves." The next day the conference was resumed. From early morning till nine at night the Elector persisted in his refusal. But the armed men who stood behind Gustavus were the most powerful of arguments. At last the Swedish king had his way. On the 15th the gates of Spandau were thrown open to his troops.
§ 8. Resistance of the Elector of Saxony.
But, if the Elector of Brandenburg had given way, the Elector of Saxony was not to be moved. He had not yet received an answer to his appeal to the Emperor; and till that arrived he would enter into no alliance with a foreigner. Further advance was impossible. Cut to the heart by the refusal, Gustavus withdrew, leaving Magdeburg to its fate.