Editors. "The Earl of Tyrone breaks his promise to submit to Queen Elizabeth". The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15511, accessed 18 May 2013.]
Hugh O'Neill, Earl of Tyrone, breaks his agreement to remain in submission to Queen Elizabeth I, and fighting breaks out in Ireland again.