MERCY, FRANZ, FREIHERR VON, lord of Mandre and Col lenburg (d. 1645), German general in the Thirty Years' War, who came of a noble family of Lorraine, was born at Longwy between 1590 and 1598. From i6o6 to 163o he was engaged in the imperial service. After distinguishing himself at the first battle of Breitenfeld (1631) he commanded a regiment of foot on the Rhine and defended Rheinfelden against the Swedes with the utmost bravery, surrendering only after enduring a five-months' siege He now became a general officer of cavalry, and in 1635, 1636 and 1637 took part in further campaigns on the Rhine and Doubs. In September 1638 he was made master-general of ord nance in the army of Bavaria, then the second largest army in Germany. In the next campaign he was practically commander-in chief of the Bavarians, and at times also of an allied army of Imperialists and Bavarians. He was made general field marshal
in 1643, when he won his great victory over the French marshal Rantzau at Tuttlingen (Nov. 24-25), capturing the marshal and seven thousand men. In the following year Mercy opposed the French armies, now under Enghien (afterwards the great Conde) and Turenne. He fought, and in the end lost, the desperate battle of Freiburg, but revenged himself next year by inflicting upon Turenne the defeat of Mergentheim (Marienthal). Later in 1645, fighting once more against Enghien and Turenne, Mercy was killed at the battle of NOrdlingen (or Allerheim) as the crisis of the engagement, which, even without Mercy's guiding hand, was almost a drawn battle. He died on Aug. 3, 1645. On the spot where he fell, Enghien erected a memorial, with the inscription Sta viator, heroern calcas.