Albrecht Wenzel Eusebius von Wallenstein ; Czech: Albrecht Václav Eusebius z ValdÅ¡tejna; 24 September 1583 â 25 February 1634), also von Waldstein, was a Bohemian military leader and politician, who offered his services, and an army of 30,000 to 100,000 men during the Thirty Years' War , to the Holy Roman Emperor Ferdinand II. He became the supreme commander of the armies of the Habsburg Monarchy and a major figure of the Thirty Years' War.