At first glance, there is nothing remarkable about the battered oak cupboard that sits in an exhibition room of the regimental museum of the 11th Royal Hussars in Winchester. It is about five foot high, the same in width and about 18 inches in depth.

But this unremarkable piece of furniture played a key part in one of the most fascinating but least known escape stories of the first World War. For three years the cupboard was home to an Irish soldier in the Royal Hussars called Patrick Fowler. He was sheltered by two French women, who knew that discovery would lead to the firing squad for all of them.

Now this story of selfless courage and endurance is to be made into a £3.5 million movie to be shot at Shepperton Studios for release late next year. It is certain to arouse much public interest in a fascinating story that has hardly been heard, not least in Dublin, where Patrick Fowler was born.

The story begins in northern France after the Battle of Le Cateau in December 1914, when three mounted troopers of the 11th Hussars became separated from the rest of their squadron behind enemy lines. Completely lost, and with the Germans everywhere, they decided to abandon their horses and make their separate ways back.

One of them, Private Patrick Fowler, spent more than a month hiding in thickets, haystacks and hedges until he was discovered by a French peasant farmer. Bearded and filthy, he was a shocking sight, but the farmer immediately decided to help, taking him to the only house in the locality that might be big enough. It was a small four-room cottage in the village of Bertry, the home of the farmer's mother-in-law, Madame Belmont-Gobert, and her other daughter, Angele.

Despite being an impoverished widow with little food to spare, Mme Belmont-Gobert didn't hesitate in agreeing to hide Fowler.

No sooner had she done this than a troop of German soldiers arrived in the village and announced that they intended to billet themselves there. The dazed Fowler was quickly bundled into the family armoire, a large cupboard that stood against the wall in the kitchen/sitting room. The cupboard was divided into two, with food and linen being kept on one side. As he crouched down in the darkness, Fowler could have had no idea that the cupboard was to be his home for most of the next three years.

Fowler could not sit or stand up and had to breathe through a semi-circular hole cut into the partition separating him from the food section. He would emerge occasionally to eat and stretch his limbs while the Germans slept upstairs.

The Germans were in the habit of searching the house as the mood took them and, to alleviate their suspicions, Mme Belmont-Gobert kept the pantry section door open. Often the Germans would sit around the fire or creep downstairs to steal food from the pantry.

There were many close calls. One feldwebel noticed that the Madame kept a close eye on the armoire and joked that she must have a secret store of food. A neighbour's dog developed a close interest in the armoire and pawed at the door, thankfully when no Germans were around.

Food, too, was always a problem. Mme Belmont-Gobert kept two hens but had to supply the Germans with an egg a day and was fined a mark for each day she failed to do so. Consequently, there was barely enough to feed the two women of the household, but still they managed to supply Fowler with scraps through the hole in the cupboard and late at night if the coast was clear.

Fowler's day-by-day terror can only be imagined but if the strain on him was immense, it was no less so on the mother and daughter, who knew exactly what to expect if caught harbouring an enemy soldier. Corporal Herbert Hull, who had been with Fowler when he became lost, was shot by firing squad in 1915 after he was discovered in the same village hiding in the roof of a garden shed. The woman who hid him was also sentenced to death, though this was later reduced to 20 years' hard labour by the Germans.

Eventually, the nervous strain began to tell on Mme Belmont-Gobert and she collapsed several times with anxiety attacks.

In this nerve-wracking fashion, the household passed the next three years until October 10th, 1918 when a troop of 11th Hussars - coincidentally Fowler's own regiment - liberated the area from the retreating Germans. Fowler, by this time dishevelled and possibly temporarily unhinged from his ordeal, emerged into the open gesticulating wildly - and was promptly arrested by a South African sergeant who was baffled by his Irish brogue and thought he might be a spy.

While being marched down the road for interrogation, Fowler was recognised by a Hussars major on horseback who was able to confirm his identity.

Fowler had got married shortly before the war and had two baby daughters. His wife, who had no idea what had happened, had been told he was missing presumed dead and was living on a widow's pension. Fowler returned to light regimental duties and, after he retired from the army, continued in the service of a Hussars major, Robert Bruce, who had a house in the tiny Scottish village of Dunphail, about 20 miles east of Inverness. He died in 1964, aged 88. Mme Belmont-Gobert received the thanks of the regiment in the shape of an inscribed silver plate. At the regiment's urging, the War Office agreed to bend the rules regarding civilian billeting of its soldiers so that she could be paid the standard two shillings a day - backdated three years.

The story did not reach the public until 1927 when two reporters looked into it. A fund was set up and the women were given a reception by the Lord Mayor of London, at which they were presented with £3,400 donated by the general public. Mother and daughter were also received by the king and queen at Windsor, where both were awarded the OBE by a grateful nation.

Today, Fowler's granddaughter, Edith Cook, lives in the Morayshire town of Forres in Scotland. She is delighted by the upsurge of interest in her grandfather, although she admits she is so familiar with the story she may have forgotten how amazing it was.

"My grandfather died when I was young, so I never got a chance to have a discussion with him about what happened," she says. "But I do remember it being said that he never talked about his wartime experiences at all.

"The day-to-day terror he must have been living in is almost unbelievable. But if it left any deep scars, they were not obvious. There was no suggestion that it had left him in shock or traumatised. I suspect that old soldiers of his generation had their own ways of coping. "He never even talked about his life in Dublin, although it seems he was an only child and that there were no other relatives."

For British film producer Bill Shepherd, the story is simply one of nobility and courage. "I was struck by the down-to-earth courage of what the women did. The sheer simple decency of it. I heard of this story some time ago and it stayed with me," he says.

Filming of Close Quarters will take place in France and Shepperton Studios from next February.

The curator of the Hussars Museum in Winchester, Major Patrick Beresford, says that the regiment had a tradition of recruiting in Ireland, where it was stationed for many years so as to take advantage of the marvellous "cavalry country". An Irishman himself, from Naas in Co Kildare, Beresford adds that the armoire is still one of the most popular exhibits and Fowler's story causes as much amazement today as it ever did.