Editors. "Dom Pedro takes Oporto with French and British aid". The Literary Encyclopedia. First published 30 December 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=17973, accessed 18 April 2014.]
Pedro I of Brazil, who has abdicated in favour of his son in order to return to Portugal to help his daughter Maria II, takes Oporto with the aid of France and Britain. The forces of his rival brother Dom Miguel are defeated.