ALBRECHT WENZEL EUSEBIUS, Duke of Mecklenburg, Friedland, and Sagan, and Count of Waldstein, or Wallenstein, was born at Prague in 1583. He belonged to an old Bohemian family, zealously attached to the Protestant religion, of which he was destined to become a dangerous opponent. He received his early education in the Protestant seminary of Goldberg, in Silesia, and subsequently at the university of Altorf; but he had no predilection for learning, and manifested in youth the same restless, ambitious spirit which characterized him through life. According to the custom of the time, he entered, as a page, the family of the Margrave of Burgau, and shortly afterwards renounced his religion and became a convert to the Roman Catholic faith. The margrave signalized his approbation of this step by providing him with the means of making an extensive tour through the chief states of Europe. His first appearance as a soldier was in 1606, when he served in the imperial army against the Turks with considerable distinction. His campaign was followed by his marriage with a wealthy widow considerably his senior, who, however, died shortly afterwards, leaving her not very disconsolate husband master of a large fortune, which enabled him to make a conspicuous figure at the imperial court. In 1617, he assisted the Archduke Ferdinand (afterwards emperor) against the Venetians with 200 cavalry maintained at his own expense, and thus acquired a high place in the favour of one who was afterwards his imperial master. On the breaking out of the thirty years' war, Wallenstein found the field for his ambition for which he had so ardently longed. He distinguished himself so greatly by his services against the revolted Bohemians, that the emperor, in 1623, invested him with the dignity of Prince of Friedland, in Bohemia. At the commencement of what may be called the second stage of the war, when Christian of Denmark came forward to support the Protestants, the genius of Wallenstein was again in request. He offered to maintain an army of 50,000 at his own expense, on condition that he should be commander-in-chief, and should be allowed to retain the contributions exacted from the conquered countries. Such a proposal, from a man so daring and ambitious as Wallenstein, might well excite alarm, but the emperor had no alternative, and closed with it. Wallenstein was soon at the head of a large force, with which he swept the districts of Saxony and the Upper Rhine that were opposed to the emperor. His career was one of rapid conquest. He defeated Count Mansfeld; compelled the King of Denmark to retreat; conquered the duchy of Mecklenburg, and parts of Holstein and Jutland; and occupied Pomerania. The want of a fleet alone prevented him invading the Danish isles; and the Hanse Towns refused to supply him with vessels. The tide of success now began to ebb. Twice he unsuccessfully besieged Stralsund, being repulsed on both occasions with great loss. The emperor was jealous of him; and his overbearing insolence, and insatiable extortions, which had not been confined to hostile districts, disgusted the German princes, who in the Diet at Ratishon, in 1530, compelled the emperor to deprive Wallenstein of his command. Disappointed, but not desponding, the victorious general resigned his post, and lived in Prague in retirement, but with all the pomp of royal dignity. His loss was soon felt Gustavus Adolphus had espoused the failing cause of the Protestants; and Tilly, who had succeeded Wallenstein as generalissimo, after unsuccessfully opposing the valiant Swede, had fallen in the field. Wallenstein only could save the empire; and the emperor was compelled to restore him to his former power, and that on terms which made him virtually the head of the empire. He immediately set out Waller. to oppose Gustavus, and after some skirmishing engaged on the field of Lutzen (November 1632), where the Swedish sovereign was victorious, but fell in the action. A sudden change now came over Wallenstein's conduct; he refrained from all active measures against the enemy, and suspicions began to be entertained of his intentions. He was accused of treason before the emperor; he replied by summoning a council of war before whom he laid all his complaints against the emperor's treatment of him; and the emperor in his turn deprived him of his command and outlawed him. Wallenstein was proceeding to open hostilities, when he was assassinated by some of his own soldiers. He fell, February 25, 1634. His character is familiar to all who have read the dramas of Schiller. For an attempt to prove the innocence of Wallenstein of the treason with which he was charged, see Dr Foster's Wallenstein's Briefe, 3 vols. 8vo, Berlin, 1828-29; and Wallenstein, &c. by the same author, 1 vol. Potsdam, 1834.