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.
Editors. "France invaded by Imperial forces". The Literary Encyclopedia. First published 01 March 2010; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9943, accessed 18 April 2015.]