Editors. "Supplementary Treaty of Vienna". The Literary Encyclopedia. First published 01 April 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=17296, accessed 20 April 2014.]
Spain and the Holy Roman Empire sign a supplementary Treaty of Vienna, in which Emperor Charles VI agrees to help Spain regain Gibraltar, and Spain offers protection for the Ostend Company. Both treaties are setbacks for French and English discussions at Cambrai.