War between Hapsburg and Valois (-1526) breaks out in Italy with the invasion of French-occupied Milan by imperial and papal armies under Prospero Colonna.
Citation:
Editors. "France invaded by Imperial forces".
The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9943, accessed 21 May 2013.]