The network was so extensive that the historian Stephen Alford – who has been hunting down Elizabethan spies and painstakingly reconstructing Cecil’s illicit files about each “intelligencer” ever since he found the list in the archives nearly 15 years ago – thinks it was “the first properly organised secret service” in England.”
https://www.theguardian.com/world/article/2024/jun/29/uncovered-428-year-old-secret-dossier-reveals-elizabeth-is-network-of-spies