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
Duchy of Limburg Eighty Years' War, ended by the 1648 Peace of Westphalia. An area known as Limburg of the States, consisting of parts of Overmaas (but no part of the Duchy of Limburg itself), was ceded to the Dutch Republic. In 1661, the Dutch and the Spanish agreed on a re-partition of the county of Dalhem. The duchy of Limburg itself remained undivided under Spanish Habsburg rule as part of the Southern Netherlands, passing to the Austrian Habsburgs under the Treaty of Utrecht in 1713. When the region was occupied by the French in 1794, the Austrian duchy of Limburg proper was