Battle of Breitenfeld

The Battle of Breitenfeld or First Battle of Breitenfeld, was fought at a crossroads near Breitenfeld approximately 8 km north-west of the walled city of Leipzig on 17 September, or 7 September, 1631. A Swedish-Saxon army led by King Gustavus Adolphus of Sweden and Saxon Elector John George I defeated an Imperial-Catholic League Army led by Generalfeldmarschall Johann Tserclaes, Count of Tilly. It was the Protestants' first major victory of the Thirty Years War.

Sweden entered the Thirty Years' War in 1628 in an attempt to prevent the Holy Roman Emperor Ferdinand II from expanding his power to the Baltic Sea and threaten Swedish territory. King Gustavus Adolphus landed with a Swedish army in the Duchy of Pomerania in 1630 to intervene in favor of the German Protestants.

Source: Wikipedia