Kingdom of France Spain and the Holy Roman Empire during the Thirty Years' War (1618–48) which had broken out in Germany. After the death of both king and cardinal, the Peace of Westphalia (1648) secured universal acceptance of Germany's political and religious fragmentation, but the Regency of Anne of Austria and her minister Cardinal Mazarin experienced a civil uprising known as the Fronde (1648–1653) which expanded into a Franco-Spanish War (1653–59). The Treaty of the Pyrenees (1659) formalised France's seizure (1642) of the Spanish territory of Roussillon after the crushing of the ephemeral Catalan Republic and ushered a short period of peace. The
Pomeranian War Frederick's downfall and to humiliate and destroy the Swedish queen Louisa Ulrika of Prussia, Frederick's sister. The Hats faction was also encouraged to declare war by France, whose wishes were central to the Hats' actions. Frederick's invasion of Saxony in 1756 was used as a pretext for war, being denounced by both Sweden and France as a violation of the Treaty of Westphalia of 1648, of which they were both guarantors. On March 21, 1757 the governments of France and Austria agreed a convention in which Sweden and France explained that they had to maintain Germany's freedom in line with