Editors. "Britain, France, Spain and Portugal ally in support of liberal constitutions". The Literary Encyclopedia. First published 30 December 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=17999, accessed 22 May 2013.]
A Quadruple Alliance is formed of Britain, France, Spain and Portugal, who ally in support of liberal constitutions in the Iberian Peninsula. In Portugal, Dom Miguel, uncle to the rightful Queen Maria II, is attempting to cling on to power.