During the Thirty Years War, French and Swedish forces invaded Bavaria and forced the elector Maximilian I, Duke of Bavaria to conclude the Truce of Ulm on March 14, 1647 and to renounce his alliance with the Holy Roman Emperor Ferdinand III. By the Autumn he broke the truce and returned to the Imperialists.
Truce of Ulm was a truce signed in Ulm on March 14, 1647.
France and Sweden invaded Bavaria during the Thirty Years' War and forced the prince-elector Maximilian I, Duke of Bavaria to conclude the truce and to renounce his alliance with Ferdinand II, Holy Roman Emperor.
By the autumn he broke the truce and returned to the empire.