The Peace of Westphalia ended the Thirty Years’ War. In December 1641 the warring parties agreed in Hamburg to hold peace talks in Münster and Osnabrück. The envoys met there from 1643. Disputes over rank and titles delayed the opening of the congress for a long time. Then the sides took more than a year to exchange their demands. The real peace negotiations began in June 1645. Both treaties were signed in Münster on 24 October 1648. The ratifications were exchanged on 18 February 1649. A separate congress in Nuremberg then worked out how to carry out the peace, until July 1650. The treaty became a fundamental law of the Holy Roman Empire. Sources differ on how many delegations took part. German Wikipedia gives about 110 delegations from 16 European states. The Münster city museum speaks of envoys from more than 150 states and territories.