Editors. "War of the German Knights against the bishoprics begins". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14297, accessed 19 May 2013.]
War breaks out between the German Knights, under the leadership of Ulrich von Hutten and Franz von Sickingen, and the bishoprics and other spiritual principalities. Von Sickingen besieges Trier, but he is eventually forced to raise the siege on 14th September.