John Thurloe

John Thurloe (June 1616 – 21 February 1668) was a secretary to the council of state in Protectorate England and spymaster for Oliver Cromwell.

Thurloe was born in Essex in 1616 and was baptised on 12 June. His father was Thomas Thurloe, rector of Abbess Roding. He was trained as a lawyer in Lincoln's Inn. He was first in the service of Oliver St John, and, in January 1645, became a secretary to the parliamentary commissioners at the Treaty of Uxbridge. In 1647 Thurloe was admitted to Lincoln's Inn as a member. He remained on the sidelines during the English Civil War but after the accession of Oliver Cromwell, became part of his government. In 1652 he was named a secretary for state.

In 1653 he became head of intelligence and developed a widespread network of spies in England and on the continent. These included the Dutch diplomat and historian Lieuwe van Aitzema, the mathematician John Wallis, who established a code-breaking department, and diplomat and mathematician Samuel Morland, who served as Thurloe's assistant. Thurloe's service broke the Sealed Knot, a secret society of Royalists and uncovered various other plots against the Protectorate. In 1654 he was elected to Parliament as the member for Ely. He supported the idea that Cromwell should adopt a royal title.

In 1655 Thurloe became Postmaster General, a post he held until he was accused of treason and arrested in May 1660. His spies were able to intercept mail, and he exposed Edward Sexby's 1657 plot to assassinate Cromwell and captured would-be assassin Miles Sindercombe and his group. (Ironically, Thurloe's own department was also infiltrated: in 1659 Morland became a Royalist agent and alleged that Thurloe, Richard Cromwell and Sir Richard Willis - a Sealed Knot member turned Cromwell agent - were plotting to kill the future King Charles II.)

In 1657 Thurloe became a member of Cromwell's second council, as well as governor of the London Charterhouse school, and in 1658 he became chancellor of the University of Glasgow. After the death of Oliver Cromwell in 1658, he supported his son Richard Cromwell as Lord Protector and, in 1659, represented Cambridge University in the Third Protectorate Parliament. Later that year various parties accused him of arbitrary decisions as head of intelligence, and he was deprived of his offices. Reinstated as a secretary of state on 27 February 1660, he resisted the return of Charles II.

After the Restoration, Thurloe was arrested for high treason on 15 May 1660 but was not tried. He was released on 29 June on the condition that he would assist the new government upon request. He retired from public life but served as a behind-the-scenes authority on foreign affairs and wrote informative papers for Edward Hyde, 1st Earl of Clarendon, but he did not become part of any new government.

John Thurloe died on 21 February 1668 in his chambers in Lincoln's Inn and was buried in the chapel. His correspondence is kept in the Bodleian Library, Oxford and in the British Museum. Thomas Birch published part of it in 1742.

Thurloe Square, Thurloe Street and Thurloe Place in South Kensington are all named after him. They were built in the 1820s on land he once owned.

• He is a recurring character in the Thomas Chaloner series of mystery novels by Susanna Gregory, which show him in a favourable light.
• He is a recurring character in the Edmund Godfrey series of mystery novels by Mark Francis, which show him as an eminence grise behind Restoration politics
• He is one of the key characters in Robert Wilton's historical novel Traitor's Field, published on 1 May 2013 (UK) by Corvus, an imprint of Atlantic Books.
• He is a recurring character in the BBC television series By the Sword Divided, portrayed by actor David Collings
• He, Samuel Morland, and John Wallis are featured indirectly in the historical novel An Instance of the Fingerpost, by Iain Pears.
• He is a character in the play Cromwell, by Victor Hugo.