He is an important character in my stories – indeed he is the inspiration for them. Despite being one of the most powerful men during the English Republic, you don’t hear much of him when the Interregnum is discussed. He was secretary to Oliver St John, a prime mover on the Parliamentarian side during the Civil Wars, then became Secretary of State in the Republic and Cromwell’s right-hand man, particularly in foreign affairs, his Head of Intelligence and Postmaster-General – the last two being closely linked.

Despite the discovery of his state papers 40 years after his death (they were hidden in a false ceiling in his rooms in Lincoln’s Inn), he remains a shadowy figure with few biographies – Philip Aubrey’s Mr Secretary Thurloe (1990) appears to be the best.