Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: Arms production in this rulers lands was greatly improved by the introduction of blast furnaces there by Louis de Geer, and he maintained a shaky alliance with John George of Saxony. This ruler ended wars with his neighbors through the treaties of Knared and Stolbovo, although he was constantly at war with his cousin, Sigismund III of Poland. Axel Oxenstierna served as this rulers chancellor, and this ruler defeated Count Tilly and Albrecht von Wallenstein in battles such as Breitenfeld and Lutzen. For 10 points, name this king, the father of Christina, who led Swedish forces in the Thirty Years War.
A:
History