Hélie de Saint-Marc: Soldier who was jailed for attempting to overthrow Charles de Gaulle

Hélie de Saint-Marc fought in the French Resistance, survived Buchenwald and completed bloody tours in Indochina, Suez and Algeria, the last of which led to his involvement in the 1961 coup to overthrow President Charles de Gaulle. It cost him his career and his medals and resulted in a 10-year prison sentence, but in 2011 he insisted that he had no regrets.

Saint-Marc was a patriot who believed that honour, particularly as a soldier, should be the upholding principle and that France's colonial advances were not only for the benefit of France but for the inhabitants, too. At his trial he said, "One day not long ago we were told to prepare to abandon Algeria... and I thought of [Indochina]. I thought of villagers clinging to our lorries... of the disbelief and outrage of our Vietnamese allies. Then I thought of all the solemn promises we made in Africa, of all the people who chose the French cause because of us... of the messages scrawled in so many villages, 'The Army will protect us. The Army will stay'."

Seven years earlier Saint-Marc had been withdrawing his paratrooper regiment from Indochina but was left mentally and emotionally scarred, feeling that they had let down the local people who had helped them. Then in colonial Algeria, with the Front de Libération Nationale (FLN) increasing its attacks in Algiers, French casualties mounting and atrocities being committed by French troops, public opinion began to waver.

Saint-Marc and his fellow coup organisers sensed a strong distrust of de Gaulle's motives in Algeria, and a sense that the army was again being betrayed and its blood spilt for no good purpose. They were opposed to the secret negotiations that Michel Debré's government had begun with the FLN.

Following an approach by a retired commander-in-chief, General Maurice Challe, Saint-Marc decided with his regiment to join the coup, which was aimed at preventing French withdrawal. Three other generals were involved, Edmond Jouhaud, André Zeller and Raoul Salan. The coup attempt began on the afternoon of 21 April 1961 and lasted until 26 April.

Born into an affluent family in Bordeaux in 1922, Hélie Denoix de Saint-Marc was the youngest of seven children to Joseph, a lawyer and First World War veteran, and his wife, Madeleine. Hélie joined the Resistance at 19, running errands between Spain and the Atlantic coast, but in 1943 he was captured near Perpignan. After interrogation he was sent to Buchenwald, where he survived illness thanks to the care of a fellow-prisoner, and then to Langenstein labour camp, where he dug tunnels for Hitler's last push. Again he fell ill, but fortunately the camp was liberated in April 1945; he weighed six stone.

Returning to Bordeaux, Saint-Marc attended the military academy at Saint-Cyr and passed out in December 1947. He was sent with the Foreign Legion to Indochina, where France was two years into a colonial war that would end with humiliating defeat in 1954. He completed two tours but when the order came to withdraw he felt he and his country had let down the partisans who had supported them. He described his lingering shame as his men prised locals' fingers off the side of the trucks carrying the legionnaires away. "Men, women and children clung on, and once forced off, sat crying in the dust of the roadside," he said. They knew retribution would be swift from the Viet Minh.

Saint-Marc was recruited into France's counter-espionage service, the SDECE. In Algeria the FLN had begun attacking French settlers; stationed at Tébessa, on the border with Tunisia, Saint-Marc led ambushes and raids on FLN forces in the mountains.

With the FLN's seizure of the government buildings in Algiers in May 1958, attacking what they saw as the French government's weakness in the face of demands for Algerian independence, Charles de Gaulle was recalled to power. He visited Algeria and declared, "Je vous ai compris" [I have understood you], but he came to accept that independence was inevitable. French left-wingers were in favour and urged him to seek a way to achieve peace while avoiding loss of face.

By 4am on 22 April 1961, Saint-Marc's 1st REP regiment had secured every major intersection in Algiers and was in control of government buildings and TV and radio stations. The second phase, led by Colonel Antoine Argoud, was the seizure by parachute regiments of strategic Parisian airfields, but security services were already alerted and all landings banned. The next day de Gaulle, dressed in his old military uniform, delivered a famous rallying speech on television appealing to citizens to rally against "an odious and stupid adventure".

In Algeria many unit commanders did not support the putsch, while in France senior officers known for their support for Algérie Française were detained. General Challe urged Saint-Marc to make a run for it. "You are young, happier times will come for you," he said. "We are going to pay a heavy price. I will certainly be shot. Let me surrender alone."

But Saint-Marc had led his regiment in revolt and knew he must remain with it. A few days later they dynamited their regimental base, fired their remaining ammunition into the air and marched away to dishonour and disbandment. He received a 10-year sentence, Challe and Zeller 15 years. Salan and Jouhaud were given life sentences after going on the run.

Saint-Marc was pardoned and released in 1966; his rank and decorations were restored eight years later. In 2011 he received the Grand-Croix de la Légion d'Honneur in recognition of his charity work for the former colonial soldiers of Algeria and the Vietnamese boat people. In the years following his release, he had worked for a metallurgy company in Lyon, rising to personnel director.

In 1989 Saint-Marc's biography was published, leading to a new career speaking at conferences round the world . He wrote several books including Notre Histoire (2002), written with August von Kageneck, a former Wehrmacht officer, in which the two men discussed their differing experiences of the Second World War.

Hélie de Saint-Marc, army officer: born Bordeaux 11 February 1922; Grand-Croix de la Légion d'Honneur 2011; married 1957 Manette de Châteaubodeau (two daughters); died La Garde-Adhémar, Drôme, France 26 August 2013.