The Holy Roman Empire and Russia conclude a military alliance
against the Ottomans. The terms of this agreement offer a guarantee
of mutual aid for 30 years.
Citation:
Editors. "The Empire and Russia conclude a military alliance against Turkey".
The Literary Encyclopedia. First published 01 April 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=17304, accessed 20 June 2013.]