This ruler's "leatheren" cannon was so light, it could be drawn and served by two men. This monarch nearly drowned in the Battle of Vittsjö, and he acquired the province of Kexholm in the Treaty of Stolbovo after winning the Ingrian War. This man regained control of Livonia from Poland in the Truce of Altmark. This monarch relied heavily on his chancellor, Axel Oxenstierna. This monarch commanded the army that defeated Count Tilly at the Battle of Breitenfeld before he was killed during a cavalry charge at the Battle of Lützen. For 10 points, name this "Lion of the North," a king of Sweden during the Thirty Years' War.
a) Gustav II Adolf
b) Frederick II
c) Charles X Gustav
d) Eric XIV