The Battle of Nördlingen, fought over two days from 5 to 6 September 1634, was a major battle of the Thirty Years' War. A Imperial-Spanish force led by the Cardinal-Infante Ferdinand and Ferdinand of Hungary inflicted a crushing defeat on the Swedish-German army led by Gustav Horn and Bernhard of Saxe-Weimar.
By 1634, the Swedes and their German allies occupied much of southern Germany. This allowed them to block the Spanish Road, an overland supply route running from Italy to Flanders, used by the Spanish to support their war against the Dutch Republic. Seeking to re-open this, a Spanish army under the Cardinal-Infante linked up with an Imperial force near Nördlingen, which was held by a Swedish garrison.
Horn and Bernhard of Saxe-Weimar marched to its relief, but significantly underestimated the numbers they faced. After limited fighting on 5 September, on the 6th they launched a series of assaults south of Nördlingen, all of which were repulsed. Superior numbers meant the Spanish-Imperial commanders could continually reinforce their positions, and Horn eventually began to retreat. As they did so, they were outflanked by Imperial cavalry and the Protestant army collapsed.
Defeat had far-reaching territorial and strategic consequences. The Swedes withdrew from Bavaria, and in the May 1635 Peace of Prague, their German allies made peace with Emperor Ferdinand II. France now intervened on behalf of Sweden and the Dutch Republic, and responded by declaring war on Spain, and entering the Thirty Years' War as an active belligerent.
Work in progress...