During the Thirty Years' War Hans Ulrich von Schaffgotsch, Lord of Kynast - though a Protestant - after the 1620 Battle of White Mountain supported Emperor Ferdinand II and served as a general in the Imperial army under Albrecht von Wallenstein. After Wallenstein's persecution and assassination in 1634 Schaffgotsch as his liegeman was arrested, accused of high treason and executed one year later. Ferdinand II seized his property and had Kynast castle occupied by his troops, who resisted the attacks of the Swedish forces. Ferdinand III added new bastions to the castle in 1648 and finally restituted it to Christoph Leopold von Schaffgotsch, Hans Ulrich's son, in 1650. Still during the latter's lifetime, in 1675, the castle that has never been conquered burnt down completely after being struck by lightning and was not reconstructed.