 The principal discoverer of the Gunpowder Plot of 1605, Robert Cecil remains a controversial historic figure as it is still debated at what point he first learned of the plot and to what extent he acted as an "agent provocateur".Cecil (created Salisbury in 1605) was the younger son of William Cecil, 1st Baron Burghley by his second wife, Mildred Cooke, eldest daughter of Sir Anthony Cooke of Gidea, Essex.His elder half-brother was Thomas Cecil, 1st Earl of Exeter, and philosopher Francis Bacon was his first cousin.