Editors. "Spain raises the siege of Gibraltar". The Literary Encyclopedia. First published 01 April 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=17323, accessed 24 May 2013.]
Spain has been besieging Gibraltar in response to Britain's attempt to blockade their colony of Porto Bello, but now they are forced by a peace agreement to raise the siege.