The
Schmalkaldic League (; ) was a defensive
alliance of
Lutheran princes within the
Holy Roman Empire during the mid-16th century. Although originally started for religious motives soon after the start of the
Protestant Reformation, its members eventually intended for the League to replace the
Holy Roman Empire as their source of political allegiance. While it was not the first alliance of its kind, unlike previous formations, such as the
League of Torgau, the Schmalkaldic League had a substantial military to defend its political and religious interests. It received its name from the town of
Schmalkalden, in the German state of
Thuringia.