Editors. "Schmalkaldic League plans a military campaign against Charles V". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14478, accessed 19 May 2013.]
The Schmalkaldic League, comprised primarily of Protestant princes and rulers, holds conferences at Nordhausen (and at Frankfurt the following month), whose purpose is to plan a military campaign against Holy Roman Emperor Charles V. The League is joined by most of the principalities and cities of northern Germany.