Francis Walsingham
Sir Francis Walsingham
Sir Francis Walsingham was born in 1532 and died 1590. In 1568 he became secretary of state under Elizabeth I. He was a a disciplined protestant and was abroad during the reign of Mary I. Francis Walsingham established an efficient espionage system and was able to prevent conspiracies like the Throgmorton plot and the Babington plot against Elizabeth I.
Sources
Conyers, Read: Walsingham and Burghley in Queen Elizabeth's Privy Council. In: The English Historical Review, Vol. 28, No. 109, pp. 34-58.
http://www.bbc.co.uk/history/british/tudors/spying_01.shtml#two