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.
Citation:
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.]