Editors. "Treaty of Passau annuls the Augsburg Interim and allows Lutheranism". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14840, accessed 11 December 2013.]
In the aftermath of war against a united front of German Protestant princes combined with Henry II of France, Charles V signs the Treaty of Passau with the princes of the Protestant alliance. By its terms, the imprisoned John Frederick of Saxony and Philip of Hesse regain their freedom. Charles is forced to give up his cherished ideal of European religious unity, annulling the Augsburg Interim of 1548, and instead allowing Lutherans to practise their religion freely in Germany. He proimses to call a diet to make a permanent settlement.