Albrecht Wenzel Ensebins Von Wallenstein (Properly Waldstein), count, and duke of Friedland, Mecklenburg, and Sagan, an Austrian general, born at the family estate of Hermanitz (according to some, in Prague), Bohemia, Sept. 14, 1583, assassinated at Eger, Feb. 25, 1634. He was brought up as a Protestant, and sent to the school in Goldberg, Silesia. At his father's death he was taken into the family of his uncle Albrecht von Slavata. He afterward studied at the Protestant university of Altdorf and at the Jesuit academy of Olmütz, and law and astrology at Padua. It is not known precisely when and how he was converted to Catholicism. In 1606 he served with distinction under Basta against the Turks in Hungary. About 1607 he married a wealthy Moravian widow, much older than himself; and by her death in 1614 he became a prominent landowner. In 1617 he levied a troop of cavalry at his own expense, and relieved the town of Gradisca, then hard pressed by the Venetians. He affiliated with the clique that was striving to undermine Cardinal Klesel's power at Vienna and raise Ferdinand of Styria to the throne. He married a daughter of Count Harrach, and was made count and chamberlain. Klesel was removed from the privy council, and in 1619, on the death of Matthias, Ferdinand became emperor.

Wallenstein had been appointed general of the forces in Moravia. Refusing to join the Bohemian insurrection, which opened the thirty years' war, his troops deserted him; but he carried off the military chest of 90,000 thalers, and with part of the money equipped a fresh regiment of cuirassiers. His regiment took part in the battle of the White mountain, near Prague, in 1620, but he himself was not present. This battle crushed the hopes of the Bohemian insurgents, and Ferdinand ordered a sweeping confiscation of their estates and a sale by auction. Wallenstein, who had carefully husbanded his means, became purchaser to an almost incredible extent. The nominal value of the estates he bought was 7,000,000 florins, but the real value was not less than 20,000,000. In 1623 he received the title of prince of Friedland; his possessions comprised nine towns and 57 villages and manors in Bohemia, toward the Silesian frontier. In 1627 he was made hereditary duke of Friedland, with almost sovereign rights; he also acquired Sagan in Silesia. In 1625 the force of the Catholic reaction was spent. The Protestant princes of North Germany had formed a powerful coalition with Denmark, and the Turks and Transylvanians under Bethlen Gabor threatened to overrun Austria from the east.

The imperial treasury was empty, and the army disorganized. Wallenstein offered to raise and equip an army of 20,000 men, and lead them whithersoever the emperor might direct. The offer was accepted, and he was appointed generalissimo. On April 15 (O. S.), 1626, he drove back the renowned Mansfeld at Dessau with heavy loss, and closely pursued him through Silesia into Hungary. Mansfeld died on his way to Venice to obtain subsidies, and the aggressions of Bethlen Gabor were checked by difficulties with his Turkish allies. By a series of manoeuvres Wallenstein dispersed the remnant of Mansfeld's troops in Silesia and defeated the Danish troops in Holstein and Schleswig at Heiligenhafen, Pinneberg, Breitenburg, and Wensyssel. The Danish army was completely scattered or captured and the North German coalition broken up. Tilly, the leader of the Catholic league formed by Maximilian of Bavaria, having been disabled by a wound, Wallenstein had the sole direction of affairs. His troops overran lower Saxony, Mecklenburg, and Jutland, and besieged Stralsund; but he was compelled to raise the siege on Aug. 3, 1628. His army, numbering over 100,000 disciplined troops, was quartered over North Germany. The dukes of Mecklenburg, who had been allies of Christian IV. of Denmark, were dispossessed, and their lands pronounced forfeited.

Wallenstein was invested with the title and dignity of duke of Mecklenburg, at first provisionally, then definitively (1629), with full powers. But his very success led to his temporary downfall. The emperor Ferdinand II., desirous of having his son declared king of the Romans and successor to the throne, in the summer of 1630 convened the electoral conference of Ratisbon. The electors, Catholic as well as Protestant, groaning under Wallenstein's enormous exactions and jealous of his might, and also unwilling to recognize him as prince of the empire in his capacity of duke of Mecklenburg, combined against him. Eichelieu, through his agents at Ratisbon, held out hopes of a general peace, and intrigued with the electors. Ferdinand yielded to the coalition and accepted their conditions, the chief of which was the dismissal of Wallenstein. In doing so, he acted against the advice of the Spaniards, who regarded Wallenstein as their strongest ally against the French. Wallenstein retired to his residence at Gitschin, followed by many of his best officers, and lived in princely state, doing much to improve agriculture, manufactures, and education.

Tilly, who succeeded him in the command, was utterly routed by Gustavus Adolphus at Breitenfeld, near Leipsic, Sept. 7 (0. S.), 1631. Shortly before the battle Wallenstein endeavored to obtain from Gustavus Adolphus a detachment of 12,000 troops, pledging himself to attack the emperor in Bohemia; but the negotiations fell through. The battle of Breitenfeld spread terror over Austria. The emperor, ignorant of the treasonable negotiations with Gustavus, turned to Wallenstein as his only hope. The general, jealous already of Gustavus's power and perceiving the opportunity of gratifying his own ambition, consented to take command for three months and reorganize the imperial army. Of the terms which he exacted the principal point was the repeal of the edict of restitution. This edict, passed by the emperor in 1629, restored to Catholicism all church property that had been converted to Protestant uses since the peace of Passau, 1552. Wallenstein, who was a man of broad views and hostile to ultramontane influences, though not free from superstition and even addicted to astrology, had opposed the edict as impolitic; and the bitter feeling it aroused in North Germany had a large share in Gustavus's success. By the spring of 1632 a new imperial army was ready for action.

Wallenstein then tendered his resignation, pleading ill health, doubtless merely as a feint to obtain greater powers. According to Ranke, the emperor conferred upon him the right of confiscation, amnesty, pardon, and supreme military authority in Germany, and the right to negotiate peace and appoint officers below the rank of general. By the end of May Wallenstein had driven the Saxons out of northern Bohemia, and he then threw himself upon Nuremberg. Gustavus, who had defeated Tilly a second time at the Lech and overrun Bavaria, hastened to the relief. For more than two months the two great generals lay confronting each other in intrenched camps. At last Gustavus made a desperate attempt, Aug. 24, to force Wallenstein's position, but failed. Shortly afterward he withdrew, leaving a strong garrison in the city. Both armies were terribly reduced by pestilence and want of provisions. Gustavus attacked Bavaria once more. Wallenstein, instead of confronting him, marched into electoral Saxony. Gustavus followed in rapid marches. The two armies met at Lutzen, not far from Leipsic. Wallenstein recalled Pappenheim, whom he had sent on a predatory expedition. Gustavus's attack was made on the morning of Nov. 6 (O. S.), 1632, before Pappenheim's cavalry reached the field.

The battle was the bloodiest and most desperate of the war, and neither side could claim the victory. Gustavus and Pappenheim fell. But Wallenstein's army was crippled, and decamped in the night, leaving its artillery. Wallenstein retired to Prague, where he held a court martial, executed 17 officers for cowardice, degraded others, and rewarded those who had shown ability and courage. He passed the winter and spring in reorganizing his army; but the Swedes were almost as formidable as ever, and the entire summer of 1633 was passed in negotiations. On one occasion only, at Steinau, Silesia, in October, did he assume the aggressive, by capturing a Swedish detachment under Duval and Thurn. Even this was of little avail, for Bernhard of Weimar, suddenly collecting his troops in Franconia, captured Ratisbon, Nov. 5. Wallenstein fell back upon Pilsen, and put his army in winter quarters in northern Bohemia. The court and the Spanish ambassador at Vienna became mistrustful, but the emperor's faith was not yet shaken.. Wallenstein seems to have been persuaded that the foe most to be dreaded was Richelieu, and that the peace of which the emperor was sorely in need could not be effected without making France a party, which was contrary to the wishes of the Spaniards. While he was negotiating with the Saxon general Arnim (or Arnheim), Oiiate, special envoy at Vienna from Milan, was working upon the emperor to order troops to be sent to the Low Countries. This was contrary to the terms of Wallenstein's command, and he declined to obey.

Feeling that his position was becoming insecure, he pushed the negotiations with Saxony to a point where they became, if not exactly treasonable, at least hostile to the supremacy of the emperor. Onate's demand for troops was made early in January, 1634. Wallenstein submitted it to a council of officers, who denounced it as impracticable, and signed a declaration pledging themselves to stand by the general. There is little doubt that he contemplated joining Arnim and compelling the emperor to accept peace. Kinsky, professing to act as his agent, had submitted to Richelieu a plan for proclaiming Wallenstein king of Bohemia. The general himself seems to have given it scarcely any attention, though Oiiate succeeded in convincing the emperor that he was acting in a treasonable manner. With great reluctance Ferdinand consented to his deposition. Gallas was made provisional commander-in-chief, and letters patent were issued releasing all officers from obedience to Wallenstein. The proceedings were conducted with the utmost despatch and with perfect secrecy, and Gallas, Piccolomini, Aldringer, Colloredo, and the other leading officers were won over.

On Feb. 19 Wallenstein issued orders to the heads of regiments to assemble at Prague, where he hoped to meet Arnica. But the commander at Prague, who had been secretly instructed by Gallas and Aldringer, published the news of Wallenstein's dismissal, and the garrison remained loyal. Other garrisons did the same. All at once Wallenstein perceived that the army upon which he relied had failed him, and his plans had been thwarted. It was no longer a question of might with him, but of life and death. He set out for Eger, Feb. 22, accompanied by only a few troops and a few firm adherents, Terzky (or Trzka), How (or Illo), Kinsky, and Neumann. On the road he met Butler, colonel of a regiment of dragoons, and ordered him to join the party. Butler, already in communication with Piccolomini, obeyed reluctantly. Wallenstein reached Eger on Feb. 24. That same evening he informed Leslie, one of the officers of the garrison there, of his intention to remain and await the arrival of Bernhard of Weimar. The next morning Gordon, the commanding officer, Leslie, and Butler were invited by Ilow and Terzky to a conference, in which they were formally summoned to take sides with Wallenstein. They were in great perplexity.

Leslie and Gordon, Protestants and Scotchmen, felt themselves nevertheless bound by their oath to the emperor; Butler was an Irish Catholic and opposed to Wallenstein. The three held a secret meeting. They could not flee without being derelict to their duty, they could not hope to make Wallenstein a captive; every moment was precious, for Bernhard, who had been informed by Ilow of Wallenstein's flight and extremity, was on the way. In the heat of discussion Leslie uttered the decisive words: "Let us kill the traitors!" The resolve was promptly executed. Ilow, Terzky, Neumann, and Kinsky were invited by Gordon to a banquet that evening in the citadel. During the banquet the doors were thrown open, a company of Butler's Irish dragoons armed with skenes were let in, and in a few moments the guests were massacred. An Irish captain, Devereux, taking a few soldiers with him, proceeded to the house where Wallenstein lodged, and burst into his apartments. Wallenstein, who had undressed for the night, was standing by the window. Devereux exclaimed, " Scoundrel and traitor!" and without a word Wallenstein opened his arms and received the fatal thrust of his halberd. - The conduct of Wallenstein has always been one of the vexed questions of German history.

Forster, especially in his "Wallenstein before the Tribunal of the World" (1844), endeavored to establish the general's innocence. Upon the strength of his investigations, Count Waldstein-Wartenburg began a suit for the recovery of the estates which were confiscated at the general's death, but the claim was not sustained. Ranke has treated the question alinost exhaustively, and in a spirit of perfect impartiality. Wallenstein left a widow and one daughter, a girl of ten years, who married Count Kaunitz. - F. Forster has edited Wallenstein"s Briefe (3 vols., Berlin, 1828-'9). See also Hurter, GescHchte Wallensteins (Schaffhausen, 1855), and Wallensteins vier letzte Lebensjahre (Vienna, 1862); Ranke, Geschichte Wallensteins (Leipsic, 1869); Hart's edition of Schiller's " Wallenstein " (New York, 1875); and Gindely, Neues über Wallenstein (1875-'6).