International relations, 1648–1814 and cultural achievement. Historian Frederick Nussbaum says it was: The worst came during the Thirty Years' War, 1618–1648, which had an extremely negative impact on the civilian population of Germany and surrounding areas, with massive loss of life and disruption of the economy and society. Scholars taking a "realist" perspective on wars and diplomacy have emphasized the Peace of Westphalia (1648) as a dividing line. It ended the Thirty Years War (1618–1648), where religion and ideology had been powerful motivating forces for warfare. Westphalia, in the realist view, ushered in a new international system of sovereign states of roughly equal
Stralsund Treaty of Stettin (1630), the town became one of two major Swedish forts in the Duchy of Pomerania, alongside Stettin (now Szczecin, Poland). After the war, the Peace of Westphalia (1648) and the Treaty of Stettin (1653) made Stralsund part of Swedish Pomerania. Lost to Brandenburg in the Battle of Stralsund (1678), it reverted to Sweden in the Treaty of Saint-Germain-en-Laye (1679). In the Great Northern War in 1715 Charles XII led the defence of Stralsund for a year against the united European armies. Stralsund remained under Swedish control until the Battle of Stralsund (1807), when Napoleon Bonaparte's army occupied