There still remained, however, the serious question whether Wallenstein would accept his dismissal. His huge and ever-growing army was absolutely under his control. His influence over the troops was extraordinary. A firm believer in astrology, he asserted that the stars promised him certain success, and his followers believed him. Tall and thin, dark and solemn, silent and grim, wearing a scarlet cloak and a long, blood-red feather in his hat, he was declared by popular superstition to be in league with the devil, invulnerable and unconquerable. No evil act of his soldiery did he ever rebuke. Only two things he demanded of them--absolute obedience and unshaken daring. The man who flinched or disobeyed was executed on the instant. Otherwise the marauders might desecrate God's earth with whatsoever hideous crimes they would. His troops laughed at the idea of being Catholics or Protestants, Germans or Bohemians; they were "Wallensteiners" and nothing else. Even Ferdinand would scarcely have dared oppose his overgrown servant had not Wallenstein failed in an attempt to capture Stralsund. This little Baltic seaport held out against the assaults of his entire army. Wallenstein vowed that he would capture it "though it were fastened by chains to heaven." But each mad attack of his wild troopers was beaten back from the walls by the desperate townsfolk; and at last, with twelve thousand of his men dead, he retreated from before the stubborn port. A superstitious load was lifted from the minds even of those who pretended to be his friends. Wallenstein was not unconquerable. He accepted the Emperor's notice of removal with haughty disdain. He said he had already seen it in the stars that evil men had sowed dissension between him and his sovereign, but the end was not yet. He retired to his vast estates in Bohemia, and lived at Prague with a magnificence exceeding that of any court in Germany. His table was always set for a hundred guests. He had sixty pages of the noblest families to wait on him. For chamberlains and other household officials, he had men who came from similar places under the Emperor. Meanwhile a new defender had sprung up for exhausted Protestantism. Gustavus Adolphus, King of Sweden, invaded Germany in 1630 and called on the Protestants to help him in the fight to save their faith. All Europe had grown afraid of the tremendous and increasing power of the Hapsburg Emperor. Not only was Protestant England in league with the Swedes, but Catholic France, under its shrewd minister, Richelieu, also upheld them. Still the burden of actual fighting fell upon Gustavus Adolphus, who proved himself the greatest military leader of the age, and, in the eyes of Protestant Europe, the noblest and sublimest man since Luther.