Editors. "The Catholic League of Halle is formed". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14511, accessed 24 May 2013.]
A Catholic League of Halle is formed in opposition to the predominantly Protestant Schmalkaldic League, led by Elector Joachim I of Brandenburg and George, Duke of Saxony.