Editors. "A Spanish force recaptures Bonn from John Casimir". The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15380, accessed 24 April 2014.]
In the Cologne War over the religious identity of the electorate, the city of Bonn had been captured for the Protestant cause the previous December. However, now it is recaptured by a Spanish force campaigning on behalf of the Catholics.