Deep in the Provençal countryside, veterans of the Foreign Legion are spending their twilight years making wine and olive oil.

They are France’s answer to the Chelsea pensioners — except that their retirements are spent on a 544-acre estate with a 17th-century chateau, vineyard and olive groves.

The Domaine Capitaine Danjou, close to Aix-en-Provence, was established in 1954 to cope with a flood of legionnaires injured in Indochina and initially had close to 400 residents. Officially known as the Institution des invalides de la Légion étrangère, it is home these days to just 80 veterans, either in need of convalescence or rehabilitation or simply a roof over their heads; the youngest is 36, the oldest 96.

These boots are made for stomping …

A recent visit to the domaine in Puyloubier, 25 miles north of the legion’s recruiting center in Aubagne, offered a glimpse into a unique establishment whose residents come from dozens of different countries.

There are no women among them, as still remains the case with the institution in which they served.

“We don’t receive any subsidies, and it is the vines that provide the majority of the money we need to keep everything running,” said the director, Lieutenant-Colonel Olivier Madonna, 54, as we sat in his grand office, its walls covered in legion memorabilia.

Last year, the domaine produced 160,000 bottles — down from the usual 200,000 because of frost and hail — about half of which ended up on the tables of legion messes, with the rest bought by the public.

Some residents make mugs, figurines and other souvenirs that are on sale in an on-site shop, while others bind commemorative books. The institution also receives donations and bequests.

The domaine takes its name from Jean Danjou, one of the legion’s greatest heroes, who was killed during Napoleon III’s adventures in Mexico in 1863. Every April 30, in one of the highpoints of the military calendar, the wooden prosthetic hand Danjou designed for himself is taken out of its case and put on parade.

The legion, which today has nearly 9,000 members and is deployed in some of the world’s trouble spots, such as Africa’s Sahel region, was set up in 1831 by King Louis Philippe and has always been open to all, regardless of nationality. Its motto is Legio Patria Nostra (the legion is our Fatherland) but its members’ loyalty is to France.

From battling enemies to bottling wine.

Though renowned for giving a second chance to those trying to escape a dubious past, these days it is choosier about its new recruits — it rejects those with serious criminal records. Traditionally, everyone who signs the initial five-year contract is given a new name on joining and allowed to reclaim their old one only after a year. Some prefer to keep the new identity.

Last year, the domaine produced 160,000 bottles — down from the usual 200,000 because of frost and hail.

The nationalities of those who serve in the legion have changed over the decades — as has the ethnic composition of the veterans in Puyloubier.

“After the Second World War, the Germans were in the majority; then we had a period with a lot of Russians and Romanians,” said Madonna. “At present the legion is more oriented to Nepalese, Malagasy and Brazilians. In a few years, they are the ones whom we will see living here.”

Despite its name, about 10 per cent of Foreign Legion are Frenchmen — though, to comply with its statutes, they have to join under a fictional nationality, usually Belgian, Swiss, Canadian or that of another French-speaking country.

Before the legion bought the domaine, which lies near the slopes of Mont Sainte-Victoire, the land was used for growing wheat. It quickly became clear that making wine would be much more lucrative, although the result was initially pretty rough.

Each year, veterans harvest grapes from the estate’s 40 hectares of vines.

“Everyone used to say the wine was excellent but the first glass was enough to give you an ulcer,” admitted Jean Jacques Lalande, 65, who spent 40 years in the legion and is now in charge of the cave. That began to change, however, after a chance meeting slightly more than 15 years ago between one of Madonna’s predecessors and Philippe Baly, co-owner of the prestigious Château Coutet, near Bordeaux.

Baly’s initial impression of the wine was “disconcerting”, he revealed in an interview with Képi blanc, the legion’s magazine. But he and Bertrand Léon, whom he brought in from the nearby Château Les Trois Croix, have since applied their expertise, and quality has dramatically improved.

Traditionally, everyone who signs the initial five-year contract is given a new name on joining.

“They are both admirers of the legion and decided to get involved and become our advisers,” Madonna said. “We are in touch almost every day.”

The colonel himself had no experience of wine making before taking up his position last summer, but is learning fast and has progressed step by step from being a “wine lover” to a “connoisseur”.

Under the institution’s rules, any veteran who has left the legion with a certificate of good conduct, and is prepared to live a bachelor existence, may live at Puyloubier, whose residents have their own self-contained studios but eat and socialize together. They are also required to make a contribution to their upkeep out of their military pensions.

The legion’s determination to look after its own reflects the esprit de corps of an organization whose code of honor ends with the phrase: “You will never abandon your dead, your injured or your arms.”

It turns out that grapes are more lucrative than wheat.

By definition far from home, the men tend to develop far closer bonds with each other than is the case in regular armies. This is reflected in some of their traditions — which includes the French practice of eating an evening meal on Christmas Eve with their comrades rather than their families. Last year was no exception: Madonna brought in “some dancing girls” to entertain them.

Not surprisingly, perhaps, given the occasionally murky motivations for joining the legion, some veterans are unwilling to go into detail about what they did in their previous lives.

Among them is John, 63, from London, who signed up in 1981 because of “some personal things, a few mistakes”, which, all these years later, he was still reluctant to go into. He did so in time-honored fashion, by knocking on the door of a legion base in Corsica.

There followed a 16-year career that included a stint in Rwanda during the 1994 genocide. After a variety of other jobs, including working as a karate instructor in Asia, he ended up in Puyloubier two years ago, where he has stopped drinking, become a vegan and is in charge of the chickens. The mix of nationalities makes it like serving in the legion itself, he said, “but without the shouting”.

Even more taciturn is Vladimir, 36, who was injured in the leg while fighting for the legion and now helps others who have been wounded. Summoned by Madonna, he had no alternative but to talk, but declined to reveal the place where he was hurt or indeed his nationality.

“Just say I am from the Soviet Union,” he said. As we left, he came up to us and asked us not to use his surname either.

Peter Conradi is the foreign editor for The Sunday Times of London. He is also the author of The Red Ripper and Hitler’s Piano Player