Editors. "Dom Miguel's supporters in Portugal force Costa Cabral into exile". The Literary Encyclopedia. First published 30 December 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=18098, accessed 25 May 2013.]
In Portugal, a popular revolt in the north of the country forces prime minister Costa Cabral into exile. In accordance with the terms of the Quadruple Alliance of 1834, Britain responds by sending a squadron to Oporto to suppress the rising.