He had the entire German naval archive at his disposal. His team of WRNS and German emigres, usually Pioneer Corps sergeants, researched in Churchill's citadel on Whitehall. They had their job cut out for them, as there were some 60,000 files with signals, logs, diaries and memoranda. They had to work at speed as their political masters wanted evidence to put the German naval command in the dock.
It is curious that Duke was chosen. He was a major in the Royal Artillery. Why did the authorities not choose a German-speaker from the Royal Navy? Possibly the reason was that British naval officers were likely, on the whole, to be sympathetic to their German counterparts. Duke's team was able to find suitable documents to build a case against Grand Admiral Erich Raeder, Commander-in-Chief of the German navy until 1943. Raeder was sentenced at Nuremberg to life imprisonment but subsequently released in 1955. Evidence against Grand Admiral Karl Donitz, head of the German submarine service, who succeeded Raeder, was more difficult to find. Yet he too was convicted and sentenced to 10 years.
When it was decided to launch a joint project of the three Western Allies - Britain, France and the United States - to screen and publish the captured German foreign policy documents, Duke headed the British team, then stationed in Berlin. The Soviet blockade of West Berlin in 1948-49 led to the evacuation of the archives to Britain, to Whaddon Hall, near Bletchley in Buckinghamshire. By 1959, after five series of Documents on German Foreign Policy, 1918-45, had appeared, political considerations favoured the return of the archives to the Germans. They were moved to Bonn.
Duke at that point resigned, moving along the corridor from the research department of the Foreign Office to the Diplomatic Service. He served in Budapest as Second Secretary 1961-64 and, after a London posting, as First Secretary in Belgrade 1967-71. When on 9 February 1973 the UK took up diplomatic relations with the German Democratic Republic (DDR) he was appointed First Secretary to the new embassy on the Unter den Linden. This was not a prestige appointment but an interesting one. The embassy was housed in a modest building with a small staff and headed by a Charge d'Affaires. The embassy to the Federal Republic in Bonn was much more important and headed by a knight. Moreover, Britain's main presence in Berlin was in the old British Sector where the Commandant had his own large staff.
Britain, France and the US did not recognise East Berlin as the capital of the DDR, which they considered still to be under four-power control. It called for careful diplomacy. However, Berlin as a whole was an excellent place to study the state of the Cold War, Germany's past, present and possible future. Erich Honecker's DDR was also regarded as having the most advanced economy of the "socialist camp".
On his retirement Duke returned to his original interest, the German diplomatic archives. He also wrote erudite articles and gave guest lectures.
Kenneth Duke was born in 1918 and was educated at Trent College, Nottingham. He read German at St Peter's Hall, Oxford. He was commissioned in the Royal Artillery and posted to India.
In Burma in 1942 he met his future wife, Jean Adams. He was advised to put an end to their relationship. When he responded by marrying her, in 1943, he was immediately ordered back to Britain. Later she was able to follow him. Their marriage ended with her death in 1983.
Kenneth Duke, historian and diplomat: born 31 August 1918; married 1943 Jean Adams (died 1983); died 8 December 1998.