Imperial elector, although Bavaria kept the Upper Palatinate and its electoral vote. Externally, the treaties formally acknowledged the independence of the Dutch Republic and the Swiss Confederacy, effectively autonomous since 1499. In Lorraine, the Three Bishoprics of Metz, Toul and Verdun, occupied by France since 1552, were formally ceded, as were the cities of the Décapole in Alsace, with the exception of Strasbourg and Mulhouse. Sweden received an indemnity of five million thalers, the Imperial territories of Swedish Pomerania, and the Prince-bishoprics of Bremen and Verden, which also gave them a seat in the Imperial Diet. The Peace was later denounced by Pope Innocent X, who regarded the bishoprics ceded to France and Brandenburg as property of the Catholic church, and thus his to assign. It also disappointed many exiles by accepting Catholicism as the dominant religion in Bohemia, Upper and Lower Austria, all of which were Protestant strongholds prior to 1618. Fighting did not end immediately, since demobilising over 200,000 soldiers was a complex business, and the last Swedish garrison did not leave Germany until 1654. In addition, Mazarin insisted on excluding the Burgundian Circle from the treaty of Münster, allowing France to continue its campaign against Spain in the Low Countries, a war that continued until the 1659 Treaty of the Pyrenees. The political disintegration of Poland-Lithuania led to the 1655 to 1660 Second Northern War with Sweden, which also involved Denmark, Russia and Brandenburg, while two Swedish attempts to impose its control on the port of Bremen failed in 1654 and 1666. It has been argued the Peace established the principle known as Westphalian sovereignty, the idea of non-interference in domestic affairs by outside powers, although this has since been challenged. The process, or 'Congress' model, was adopted for negotiations at Aix-la-Chapelle in 1668, Nijmegen in 1678, and Ryswick in 1697; unlike the 19th century 'Congress' system, these were to end wars, rather than prevent them, so references to the 'balance of power' can be misleading. Human and financial cost of the war Historians often refer to the 'General Crisis' of the mid-17th century, a period of sustained conflict in states such as China, the British Isles, Tsarist Russia and the Holy Roman Empire. In all these areas, war, famine and disease inflicted severe losses on local populations. While the Thirty Years' War certainly ranks as one of the worst of these events, 19th century nationalists often