1642 but only became serious in 1646; a total of 109 delegations attended at one time or other, with talks split between Münster and Osnabrück. After the Swedes rejected Christian of Denmark as mediator, the negotiators finally agreed on Papal Legate Fabio Chigi and the Venetian envoy Alvise Contarini. The Peace of Münster was the first to be signed on 30 January 1648 and is considered to be part of the Westphalia settlement since the Dutch Republic was still technically part of the Spanish Netherlands and thus Imperial territory. The treaty confirmed Dutch independence, although the Imperial Diet did not formally accept that it was no longer part of the Empire until 1728. The Dutch were also given a monopoly over trade conducted through the Scheldt estuary, ensuring the commercial ascendancy of Amsterdam; Antwerp, capital of the Spanish Netherlands and previously the most important port in Northern Europe, would not recover until the late 19th century. Negotiations with France and Sweden were conducted in conjunction with the Imperial Diet, and were multi-sided discussions involving many of the German states. This resulted in the treaties of Münster and Osnabrück, making peace with France and Sweden respectively. Ferdinand resisted signing until the last possible moment, doing so on 24 October only after a crushing French victory over Spain at Lens, and with Swedish troops on the verge of taking Prague. It has been argued they were a "major turning point in German and European...legal history", because they went beyond normal peace settlements and effected major constitutional and religious changes to the Empire itself. Key elements of the Peace were provisions confirming the autonomy of states within the Empire, including Ferdinand's acceptance of the supremacy of the Imperial Diet, and those seeking to prevent future religious conflict. Article 5 reconfirmed the Augsburg settlement, established 1624 as the basis, or "Normaljahr", for determining the dominant religion of a state and guaranteed freedom of worship for religious minorities. Article 7 recognised Calvinism as a Reformed faith and removed the ius reformandi, the requirement that if a ruler changed his religion, his subjects had to follow suit. These terms did not apply to the hereditary lands of the Habsburg monarchy, such as Lower and Upper Austria. In terms of territorial concessions, Brandenburg-Prussia received Farther Pomerania, and the bishoprics of Magdeburg, Halberstadt, Kammin, and Minden. Frederick's son Charles Louis regained the Lower Palatinate and became the eighth