Francis Walsingham was an English statesman and spymaster who served as principal secretary to Queen Elizabeth I. He is known for his role in establishing a network of spies and informants to protect the queen and the Protestant cause from Catholic threats, particularly from Spain. Walsingham's intelligence operations were instrumental in uncovering several plots against Elizabeth, including the Babington Plot, which led to the execution of Mary, Queen of Scots. His efforts to protect the queen and maintain the security of England earned him the nickname "the spymaster."