The war entered its third phase by the landing of the Swedes at Usedom (June, 1630), and their conquest of Pomerania and Mecklenburg. Gustavus, by the exercise of a little wholesome pressure, induced the elector of Brandenburg to aid him; and though unable to save Magdeburg (q.v.), he marched to join the Saxons, completely routed Tilly at Breitenfeld (Sept. 17, 1631); victoriously traversed the Main and Rhine valleys; again routed Tilly on the Lech (April 5, 1632), and entered Munich. By the judicious strategy of Wallenstein he was, however, compelled to return to Saxony, where he gained the great victory of Ltitzen (q.v.); but his death, depriving the Protestants of the only man who could force the confederate powers to preserve unity of action, was a severe blow to their cause; though the genius and indefatigable zeal of his chancellor, Oxenstierna, and the brilliant talents of the Swedish generals, preserved the advantages they had gained, till the crushing defeat of Bernard of Weimar at Nordlingen (Sept. 6, 1634) again restored to the emperor a preponderating influence in Germany. Saxony DOW made peace at Prague (May 30, 1635), obtaining such satisfactory terms for the Lutherans that the treaty was within three months adhered to by all the German princes of that sect, and the Calvinists were left to their fate.
Final success now appeared to demand only one more strenuous effort on the part of Austria; but Oxenstierna, resolved to preserve to Sweden her German acquisitions, •propitiated Richelieu (q,v.) by resigning to him the direction of the war; and the conflict advanced into its final and most extended phase. The emperor, .allied for offense and defense with the Lutherans, was now also assailed through his ally, Spain, who was attacked on her own frontier, in the Netherlands, and in Italy; Bernard of Weimar fighting independently, with the -view of obtaining Alsace for himself, opposed the leaguers, while the Swedes, under Baner, held North Germany, and by frequent flying marches into Silesia and Bohemia, distracted their opponents, and prevented them, after their successes over duke Bernard, from proceeding with the invasion of France. The great victory of
Bauer over the Austrians and Saxons at Wittstock (Oct. 4, 1636), restored to Sweden the victor's wreath she had lost two years before; and from this time, especially under Tor stensohn (q.v.) and Konigstnark,. the Swedes were always successful, adding a second victory of Breitenfeld (Nov. 2, 1642), one at Yankowitz (Feb. 14, 1645), and numberless ones of less note, to their already list of successes, carrying devastation and ruin into the hereditary territories, even to the gates of Vienna, defeating the best generals of the empire, till, from a profound feeling of inability to check them, the Austrians hardly dared appear to the north of the Danube, On the Rhine the leaguers at first had great success—the Weimar troops, now in French pay, were almost exterminated at Duttlin gen (Nov. 24. 1643); but after the Spanish power had been thoroughly broken in the Netherlands by Conde, the French were re-enforced on the Rhine; and under Conde and Turenne (q.v.) rolled back the leaguers through the palatinate and Bavaria, and revenged at Nordlingen (Aug. 3, 1645) the former defeat of the Swedes. The emperor was now deserted by all his allies except the duke of Bavaria, whose territories were already mostly in the hands of Turenne and Wrangel; and a combined invasion of Austria from the w. and n. was on the point of being executed, when, after seven years of diplomatic shuffling, with an eye to the changing fortunes of the contest, the peace of Westphalia (q.v.) put an end to this terrible struggle.