The Battle of Breitenfield in this war saw the army led by Tilly suffer a disastrous defeat. After Tilly's death a year later, Frederick II sought the aid of a commander he had already dismissed, though Albrecht von Wallenstein suffered a major defeat at Lutzen by Sweden's Gustavus Adolphus. At its end, the doctrine of cuius regio, eius religio was revised to allow German princes to determine whether their constituents were Calvinist, in addition to Lutheran or Catholic. For 10 points, identify 
The Battle of Breitenfield in this war saw the army led by Tilly suffer a disastrous defeat. After Tilly's death a year later, Frederick II sought the aid of a commander he had already dismissed, though Albrecht von Wallenstein suffered a major defeat at Lutzen by Sweden's Gustavus Adolphus. At its end, the doctrine of cuius regio, eius religio was revised to allow German princes to determine whether their constituents were Calvinist, in addition to Lutheran or Catholic. For 10 points, identify this religious war that began in 1618 with a Defenestration of Prague and ended in 1648 with the Peace of Westphalia.
The Battle of Breitenfield in this war saw the army led by Tilly suffer a disastrous defeat.
{Thirty Years}' War