Denning was a prominent and pioneering figure in naval and military intelligence and established a successful career during and after the Second World War, holding many senior ranking staff positions.

Norman joined the forces, choosing the Royal Navy shortly after the end of World War I; despite his bad eyesight[1] he was accepted into the Paymaster Branch.

[4] The OIC became a key and vital element for the British intelligence services, coordinating efforts between decryption units such as the Government Code and Cypher School and the staff and command officers planning operations.

[5] Denning was appointed Officer of the Order of the British Empire (OBE) for his work in 1945, and after the war was made Director of Planning for the Admiralty.

After his retirement he spent most of his time at his home in Micheldever, and occasionally gave lectures at institutions both in the United Kingdom and overseas.

He died on 27 December 1979; after separating a pair of fighting dogs he was bitten on the hand, and the resulting tetanus jab caused a reaction which set off a heart attack.