The Battle of Breitenfeld (German: Schlacht bei Breitenfeld; Swedish: Slaget vid Breitenfeld) or First Battle of Breitenfeld (in older texts sometimes known as Battle of Leipzig), is fought at a crossroads near Breitenfeld approximately 8 km north-west of the walled city of Leipzig on 17 September (Gregorian calendar), or 7 September (Julian calendar, in wide use at the time), 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.