Editors. "The Somerville Plot to assassinate Elizabeth I is discovered". The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15291, accessed 22 December 2013.]
The Somerville Plot, which planned to assassinate Elizabeth I is discovered, and its originator, John Somerville, is executed on 20th December.