Gallas, Matthias, Graf von, 1584-1647, imperial general in the Thirty Years War. He served under Tilly, commander of the Catholic League, in Germany until 1629, and then entered Italy, helping to take Mantua (1630). He served as field marshal under Wallenstein, chief of the imperial forces, but later participated in the conspiracy that brought about Wallenstein's removal by Holy Roman Emperor Ferdinand II and his subsequent assassination (1634). Gallas succeeded to a large part of Wallenstein's duchy of Friedland and to the actual command of the armies (nominally under the emperor's son). At Nördlingen (1634) he defeated the Swedes and Bernhard of Saxe-Weimar. After 1635 his drunkenness and total incompetence caused him several times to lose his command, but he regained it each time through influence at court.