a field marshal of the Holy Roman Empire during the Thirty Years' War (1618–48). Though active in every theatre of war, he proved no match for the leading Protestant generals.

From 1625 to 1632 Hatzfeldt campaigned under the imperial generalissimo Albrecht von Wallenstein; he then took part in the conspiracy that toppled Wallenstein (1634), for which the emperor Ferdinand III rewarded him with lands and titles. From 1639 to 1643 he was successful in the secondary Rhenish-Westphalian theatre of war. Against the Swedes, however, he could do little. Johan Banér defeated him at Wittstock (1636), and Lennart Torstenson outfought and captured him at Jankov, Bohemia (1643).

Retiring in 1646, Hatzfeldt was recalled in 1657 to lead an imperial army to rescue Poland from Swedish attack. He captured Kraków but again retired because of ill health and died shortly thereafter. He was a remarkably honest and fair commander in an age of unscrupulous mercenary warfare.