Holy Roman Emperor Ferdinand II gives General Wallenstein the title
of Duke of Friedland, and makes him a Prince of the Holy Roman
Empire.
Citation:
Editors. "Frederick II makes Wallenstein Duke of Friedland".
The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15930, accessed 25 May 2013.]