The valley near Rossbach, between Reichertswerben and Braunsbedra, was the site of the 5 November 1757 Battle of Rossbach between Prussia and the Allied Armies of France and contingents of the Holy Roman Empire, fighting on behalf of Duchy of Austria during the Seven Years' War. The battle had lasted less than 90 minutes but was instrumental in knocking France out of the Silesian theater of the Seven Years' War. Less than five percent of Frederick the Great's entire force had been engaged, and it decisively defeated an army of 42,000. Frederick's use of operational maneuvers and with a fraction of his entire force—3,500 horsemen, 18 artillery pieces, and 3 battalions of infantry—had defeated an entire army of two of the strongest European powers. Frederick's tactics at Rossbach became a landmark in the history of military art. During this battle, Friedrich Wilhelm von Seydlitz emerged as one of Frederick's greatest cavalry leaders.