He used several other pseudonymns, including Peter Leighton, Peter Morland, Ronald Reckitt and Edward H Spire along with probably his most famous, E.H. Cookridge.
As Cookridge, he wrote his first book Secrets of the British Secret Service in 1948 and this contained 'some highly coloured versions of true events'.
Most of his works under the Cookridge pseudonymn are concerned with spies and spying, including books on George Blake and Kim Philby.