Editors. "John Dudley is created Duke of Northumberland". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14823, accessed 21 May 2013.]
John Dudley, Earl of Warwick, who in the wake of the fall of Protector Somerset now leads Edward VI's government, takes on the title of Duke of Northumberland.