Jean-Louis Crémieux-Brilhac, who played a key role in General de Gaulle's entourage in wartime London, has died in Paris at the age of 98, reports BBC News.
Crémieux-Brilhac spent three years at the headquarters of de Gaulle's Free French in Hill Street, Mayfair, where he was secretary of the propaganda committee.
It was in this function that he personally drew up the instructions to be read out over the BBC, telling the French public how to react on D-Day.
Crémieux-Brilhac kept the original typed document in his possession, and showed it to the BBC for a film on the 70th anniversary of D-Day last year. He said that on his death it should be bequeathed to the French National Archives.
"For a young officer like me it was something exceptional to be working at the heart of the decision-makers," he said.
Crémieux-Brilhac had already survived several adventures before joining up with de Gaulle in 1941.
A young French officer, he fought against the invading Germans in May 1940 and was taken prisoner.
He escaped from his prison-camp in Germany and made his way through Poland to Soviet territory. But as the Nazi-Soviet pact was still holding, he was promptly imprisoned again. He said conditions under the Russians were worse than under the Germans.
Crémieux-Brilhac was released again when Hitler invaded Russia in June 1941. He travelled on a Canadian ship from Archangel to Glasgow along with 200 or so other French soldiers.
Archive Pathe footage shows the group arriving by train at Euston station. Viewing the images 70 years on, Crémieux-Brilhac spotted many of his friends - but sadly not himself.
With the Free French, Crémieux-Brilhac was responsible for liaising with the BBC, which ran a daily schedule of French language propaganda broadcasts into France. Several times he took the microphone himself.
"It was the most thrilling feeling, sitting there in the studio in London, and knowing that all those hundreds of miles away your voice was being listened to in homes across France," he said.
He was born Jean-Louis Crémieux in the Paris suburb of Colombes in 1917. The Crémieux were a family from one of France's oldest Jewish communities in the former Papal states at Avignon. He added the Brilhac as a nom-de-guerre in London.