Jean-Louis Crémieux-Brilhac, who has died aged 98, was one of the last surviving members of General Charles de Gaulle’s London-based Free French movement. Although he described himself modestly as a “foot soldier”, his responsibilities, for someone so young, were actually considerable.
Crémieux was in charge of monitoring all radio broadcasts made out of occupied France and, as secretary of the Free French propaganda committee, was responsible for sending information to the resistance movements that they could use for their own propaganda. In February 1944 he wrote, and sent to France, a report that summarised all the available information on the extermination of the Jews. And in preparation for D-day he wrote broadcasts to the resistance giving them coded instructions on when to move into action to support the allies.
Crémieux (Brilhac was the resistance name he took to protect his family back in France) was born at Colombes, near Paris, into a middle-class, progressive Jewish family committed to the liberal values of French republicanism. Educated at one of the best Parisian lycées, he was a brilliant student, passionate about history and politics. He was a supporter in his teens of the leftwing Popular Front government of Léon Blum, and was mortified when that administration refused to help Republican Spain during the civil war.
Called up to join the army in 1940, he was shocked by the passive and defeatist attitude of his senior officers and later remembered that one of them had said to him: “Don’t ever do what you can get someone else to do for you, and never do today what you can leave until tomorrow.”
Taken a prisoner of war by the Germans after the French defeat in 1940, he was transferred to a camp in Pomerania, in the Baltic region, where he proudly declared his religious identity as “a freethinker of Jewish origins”.
Soon afterwards he managed to escape with two other prisoners, and they made their way 400 miles eastwards, hoping that in Lithuania they could make contact with the French authorities. But Lithuania was at the time occupied by the Red Army, and instead of being free they found themselves prisoners of the Soviet Union, which was allied in a non-aggression pact with Germany. Crémieux was transferred to the infamous Lubyanka prison, in Moscow, where the conditions were worse than they had been in Germany.
He then fetched up in another Soviet camp, where previously many thousands of Polish officers had been interned before being massacred by the Soviets at Katyn. Only when Germany invaded the Soviet Union in June 1941 was Crémieux finally released. His group of 186 French PoWs made its way on a Canadian cargo ship from Archangel to London. Many of the group would go on to play an important role in the Free French organisation and one of them, Alain de Boissieu, was to become de Gaulle’s son in law.
Their arrival in London was a considerable boost to de Gaulle’s prestige at a moment when his relations with Winston Churchill were at rock bottom. The Free French were badly lacking recruits and Crémieux immediately started working for their propaganda services.
After 1945 Crémieux was one of the founders, and then director, of an organisation called La Documentation Française. Although funded by the government, this was an independent body dedicated to providing French decision makers with up-to-date information on economic and social problems. Crémieux’s work there was part of his commitment to the enterprise of modernising France after the war, and of overcoming the weaknesses he believed had led to defeat. He also worked for a short period in 1953 for the left-of-centre politician Pierre Mendès France, who became prime minister the following year.
After retirement Crémieux embraced a prolific third career as a historian, his books combining impressive scholarship with scrupulous sceptical intelligence. In 1990 he published a massive two-volume account of the fall of France, which he followed six years later – when he was 79 – with a huge history of the Free French that showed the organisation was much more than a one-man band around de Gaulle. There were several other books, including a biography, published when Crémieux was 93, of Georges Boris, the socialist Jewish intellectual who had been one of de Gaulle’s earliest recruits in London and was later the closest aide to Mendès France.
All his books were about a history Crémieux had lived through, but it was characteristic of his modesty and intellectual rigour that he preferred to write about his own experiences only as an objective – if not dispassionate – historian.
Crémieux was a courteous man with a gentle sense of humour and an unshakeable commitment to the values of humanism and democracy. He received many decorations, including France’s highest rank, the grand croix of the Légion d’honneur. When the French president Nicolas Sarkozy visited Britain in 2010 for the 70th anniversary of de Gaulle’s first speech from London, Crémieux was the person chosen to take him round the BBC: his life had come full circle.
He was predeceased by his wife, Monique, whom he married in 1940. He is survived by three children, five grandchildren and three great-grandchildren.
• Jean-Louis Crémieux-Brilhac, resistance leader and historian, born 22 January 1917; died 8 April 2015