Albrecht Wenzel Eusebius von Wallenstein, Duke of Friedland (24 September 1583 – 25 February 1634), also von Waldstein (Czech: Albrecht Václav Eusebius z Valdštejna), was a Bohemian military leader, statesman and a major figure of the Thirty Years' War, fighting on the Catholic side as supreme commander of the armies of Holy Roman Emperor Ferdinand II. His successful martial career made him one of the richest and most influential men in the Holy Roman Empire by the time of his death. He is considered one of the most important military leaders produced by the early modern period.
Wallenstein was born in the Kingdom of Bohemia into a poor Czech Protestant noble family, affiliated with the Utraquist Hussites. He acquired a multilingual university education across Europe and converted to Catholicism in 1606. A marriage in 1609 to the wealthy widow of a Bohemian landowner gave him access to considerable estates and wealth after her death at an early age in 1614.