Extract relating to military intelligence work:
In the autumn of 1939 John entered Corpus Christi College with a Major Scholarship, a closed Exhibition and a St Paul’s leaving award. At the end of his first year, during which his studies were directed by H. D. P. (later Sir Desmond) Lee, he was awarded a First in the Classical Preliminary examination. But after the fall of France in 1940 he felt he could no longer remain a student and volunteered for the Royal Navy. He began as an Ordinary and later Able Seaman, and saw service in the Eastern Mediterranean on HMS Coventry. In 1942, however, somewhat to his surprise he was transferred to intelligence duties in Egypt, and in September of that year was promoted to Temporary Sub-Lieutenant (Special Branch), RNVSR. Most of his work initially consisted in deciphering Italian naval signals. He had been selected largely because of his knowledge of Latin which was deemed to be adequate preparation for dealing with Italian. Linguistic expertise was certainly needed: initially the group did not even have an Italian dictionary. The low-grade naval ciphers John was working on were mostly in a code named Cifrarlo per Uso di Mare, referred to affectionately by John and his colleagues as Ouzo. But transcripts of traffic in another code were also available in the office in Alexandria where he worked. These messages were prefixed by the one or other of the words GIOVE and DELFO. Strictly speaking, John ought not to have investigated this material, since instructions had been received from headquarters at Bletchley that it should be left to them to deal with. John, however, persuaded his local superior that it could be useful, for purposes of comparison with the Ouzo material, if he did take an interest in it. Much of the material in GIOVE/DELFO was routine, and could readily be deciphered. But John also noticed a much longer and clearly more important message containing many more groups than the routine traffic. Working on this with the head of his section, he was able to translate enough of it to establish that the message concerned a British submarine which had been sunk near Taranto, and attempts being made by the Italians to salvage it. This was of major importance, since if successful the enemy might well recover a copy of the British submarine code. The facts were immediately reported to the Admiralty in London, which prompted an inquiry of Bletchley why the news had come from Alexandria and not the Home Station. As John learnt much later, there were some red faces in the naval section; and Bletchley came to know the name of John Chadwick long before they saw him in person. When he was back in Cambridge after the end of the war he was sent for a supervision to L. P(atrick) Wilkinson, the Latinist at King’s College who had held an important post at Bletchley; to his amazement he was greeted with the words GIOVE, DELFO.
In John’s life code-breaking was important for what followed, but another event also had consequences. When he was at Suez in 1942 as an ordinary seaman he met a somewhat older cousin, W. N(eville) Mann, who was an officer in the Army and later became a well-known physician. There was a further encounter in Bombay but meetings were difficult because officers ‘were forbidden to associate off duty with “ratings” (Navy) and “other ranks” (Army) by “King’s Regulations”’. Nevertheless the two, who previously had hardly known each other (there was a nine year age difference), found a number of things in common and in the middle of the war in the Mediterranean kept up a correspondence, although it was slow and desultory. It was at one of their meetings that the project was formulated to translate the non-surgical works of Hippocrates, the Greek medical writer. The editor of the Loeb (Greek and English) text, W. H. S. Jones, was a distinguished Hellenist, but he was not medically trained and, as Neville told his cousin, doctors found his translation unsatisfactory. John had acquired a Teubner text in Alexandria and that was their starting point: John brought to the task his knowledge of Greek and his cousin his medical expertise. In the end the work was mostly done in calmer times between 1947 and 1950, but D. Mervyn Jones remembers being shown at Bletchley a tentative emendation in Hippocrates’ text proposed by Chadwick. It impressed him as certainly right and made him aware that after the war he was likely to meet very strong competition in his project of an academic career as a classicist. The Medical Works of Hippocrates, by Chadwick and Mann, appeared in 1950 and was John’s first publication. It was later adopted by the Penguin Classics series as their text; and it still remains in print, more than half a century later.
After the Italian surrender in September 1943 and after a short period of general duties John was sent back to England at the beginning of 1944 and began a Japanese language course at Bletchley Park. He completed it with distinction (he was one of two classical scholars who came top in the course) and was set to work with two Japanese experts at the translation of messages sent to Tokyo by the Japanese naval representatives in Stockholm and Berlin. Some of the most important of these were from the Naval Attaché in Berlin, who had access to secret reports prepared by the German navy. From his despatches Chadwick and his colleagues were able to obtain invaluable information about such matters as the new generation of U-boats that the Germans were building in 1945. The task was complicated not so much because of the difficulties of Japanese as such, but because of the subject matter: radar, night vision of pilots, espionage, railways, etc. required a knowledge of technical terms and realia which none of the group possessed; the fact that the texts were supplied in an inadequate transliteration in Latin letters made things worse. It was nevertheless a task which was successfully accomplished. To judge from his accounts of it, the young recruit never had any doubt of the importance of the work or of the fact that it was a privilege to be involved in it together with people far more expert than he was. It was impressed on him and his colleagues that the work had to be kept strictly confidential; the embargo on disclosure remained in place for many years. Until it was lifted, John never mentioned the obvious links between his war activities and his interest in decipherment, even if a number of people must have guessed it.
(See: List of humanities scholars who worked in military intelligence in the Second World War)