1653 Imperial election electoral rights in a treaty of 1619, confirmed at the Diet of Regensburg on February 25, 1623. The revolt ignited a broader religious war across Germany, the Thirty Years' War, which would involve not only the states of the empire but also Sweden, the Dutch Republic, France, Denmark–Norway, England, Scotland, Spain and Hungary and which would kill some eight million people before its end. The Peace of Westphalia which ended the war in 1648 revived the principle of "cuius regio, eius religio" established in 1555 by the Peace of Augsburg and established the modern concept of Westphalian sovereignty. It additionally
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