Includes 30,000 16th and 17th-century manuscripts from the Hatfield House Archives, consisting principally of the correspondence of William Cecil, Lord Burghley (1520-1598) and his son Robert, the 1st Earl of Salisbury (1563-1612).
These two men dominated the administration of government during the reign of Elizabeth I, to the extent that critics suggested that England was becoming a regnum Cecilianum. The collection documents their various official roles. In addition, the collection contains documents acquired by Robert Cecil that had belonged to his rival, Robert Devereux, the 2nd Earl of Essex.