As part of the Livonian War, Stephen Bathory, King of Poland,
invades Russia. He besieges the city of Pskov, arguably a risky
strategy since his army is relatively small, but it proves
worthwhile since ultimately Ivan the Terrible, feeling threatened
by this siege, cedes the Duchy of Livonia back to the
Polish-Lithuanian Commonwealth.
Citation:
Editors. "Stephen Bathory of Poland invades Russia".
The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15263, accessed 24 May 2013.]