born 1581, Boitzenburg, Brandenburg

died April 28 【April 18, old style】, 1641, Dresden, Saxony

soldier prominent in German affairs during the Thirty Years' War. He served (1613–17) with the Swedes under Gustaf II Adolf, with the Poles (1621), with Wallenstein's imperial army (1626) as a field marshal, and with the Saxons (1631–35, 1638–41). A strict Lutheran, Arnim resigned his imperial commission in protest against the Edict of Restitution (1629). Thereafter he worked for the creation of a “third party,” under the Elector of Saxony, to hold the balance between the imperial court and the encroachment of Sweden, France, and Spain, and for a plan of general pacification. He left the Saxon Army in 1635 in protest over the Peace of Prague. Arrested by the Swedes (1637), he escaped and was reinstated in the Saxon Army (1638), but he died while preparing to oust the French and Swedes from German soil.