Beneath the barley and sugar beet fields of the Somme, the bones still lie. Cemeteries are scattered about this landscape as haphazardly as were the trenches of the Great War, but thousands of the fallen were never recovered, never laid to rest beneath Portland stone.

As the surrounding towns and villages have grown over the last century, open fields have slowly been overtaken with houses. Which is how eight soldiers from the 78th Battalion of the Canadian Expeditionary Force found their resting place in Fabien Demeusere's back garden in the hamlet of Hallu, 37 miles west of Amiens.

One rainy day in 2006, Mr Demeusere, then 14, noticed something unusual in the garden and went out to investigate. There he found a handful of bullets, which the heavy rain had brought to the surface. Intrigued, he grabbed a shovel and began digging. Within minutes, he had unearthed human bones, undisturbed for nine decades.

'It was a strange feeling,' said Mr Demeusere, whose parents had told him about the war and who had started studying it at week-ends. 'I felt something in my heart.'

Last week, he stood over a trench once again. Now 24 and an officer in the gendarmerie, he had put on his smartest suit and tie to lay a wreath as eight coffins bearing the remains he discovered were lowered into place at Caix British Cemetery, just a short drive away.

After Last Post was played, he knelt to place the flowers above the grave, then bowed his head.

In the coffins beneath him, two British-born soldiers, Private Lachlan McKinnon and Private Sidney Halliday, three Canadian comrades and three others whose bones remain unidentified were finally laid to rest with the honour denied them for nearly a century.

Behind the coffins, a dozen workmen in their Commonwealth War Graves Commission uniforms stood silently throughout the service, paying their respects to the men whose graves they would shortly plant with roses and mark with the same headstones as those of their 365 comrades already buried there. In front of them stood the oldest living descendants of Ptes McKinnon and Halliday, and the other men, the conclusion of almost a decade of historical, genealogical and scientific research.

'These men liberated my village and we owe them a debt of honour,' said Mr Demeusere after the service.

Lachlan McKinnon was born in Campbeltown on the Mull of Kintyre on November 15 1888. Three hundred miles away and seven years later, in October 1895, Julia Halliday gave birth to a son, Sidney, in Apple Tree Cottage in the Gloucestershire village of France Lynch. Her husband, George, earned his living making walking canes.

Both joined the thousands of Britons who moved to Canada in 1913. McKinnon became a butcher, while Halliday followed his brother, William, who had emigrated a year earlier, by working on a farm.

In December 1915, Sidney and William both signed up. William was refused on medical grounds but Sidney was accepted, as was McKinnon, who enlisted four months earlier. They must have been delighted that their war service first saw them return home to Britain, where, in 1916, McKinnon married his girlfriend, Christina.

Soon, though, they were packing up again, and dispatched with the battalion to France. In August 1918, they were ordered to retake Hallu, which had been captured by the Germans in March.

They took the hamlet on the 10th, but the next day they were driven back in three counter-attacks by the German Alpine Corps. In this battle for the village, both Halliday, 22, and McKinnon, 29, gave their final sacrifice, along with 44 of their comrades. The battalion's war diaries only recorded the names of officers who fell, but manila 'circumstances of death' forms were filled out for both soldiers, recorded as 'killed in action'.

McKinnon's form read: 'He and four of his comrades were killed by a shell that exploded in the trench they were in.' Halliday's form explained he was killed instantly by a shell explosion, adding: 'Owing to a temporary withdrawal from the position, his body could not be recovered for burial.'

Back in Britain, their parents learnt of the loss of their sons. There was not even a grave to visit, a focal point for their grief. When McKinnon's niece, Morag, died young, Lachlan's name was added to her gravestone in Campbeltown, in lieu of his own comer of a foreign field.

And there the story might have ended, had it not been for Fabien Demeusere's passion for history.

If he were not so fascinated by the Great War, he would probably not have kept digging, that day he found the bullets. He did not know then, of course, but one of the three sets of remains he uncovered was that of Sidney Halliday.

He immediately knew who to call: in a region where farmers are almost as used to turning up unexploded ordnance as their crops, and where the remains of two or three soldiers are unearthed each year, locals regularly have to summon staff from the War Graves Commission.

They swiftly identified the remains as Canadian because 78th Battalion badges were discovered with the bones. A few months later, as the Canadian authorities began archival research to establish which soldiers died in Hallu, the bones of five more soldiers, including McKinnon, were recovered from the Demeusere family's garden.

Historians concluded that the fallen of August II were the only Canadians to die in Hallu, which allowed them to draw up a list of 45 men whose remains the bones could be. In early 2007, four months into her new job, this list was passed to Laurel Clegg, a newly qualified forensic scientist.

She examined the bones to establish how tall the men were and their age, before cross-referencing these details with data recorded when the men enlisted. This shortened the possible list of men to 15.

That task was not easy, and took several years. 'A lot of them lied about their names and ages and where they came from when they moved to Canada,' said Ms Clegg. 'One of those we successfully identified wrote his name differently four times.'

This research led her to Jim Halliday, Sidney's nephew and William's son, now 72, who continued the family tradition by farming just a few miles from where his uncle worked the land in Manitoba.

But the matrilineal DNA test carried out on one of Jim's female relatives was inconclusive, and it looked like Mr Halliday might never know for sure whether these remains were his uncle's.

Then he remembered that his uncle had exchanged rings with his girlfriend, Lizzie Walmsley. Ms Clegg was astounded: near the bones they had found a locket with the inscription: 'L. Walmsley.' 'When I finally got that call that, yes, it was him and he had been identified, that topped it all off,' said Mr Halliday.

Ms Clegg also had trouble identifying McKinnon. Genealogical research indicated that his nephew, Thomas Bolton, had a daughter, but researchers failed to trace her. Two years ago, however, they came across a post by a Tom Haynes, asking for information about Bolton. They wrote to him and discovered he was Bolton's grandson: he put them in touch with his mother, Maureen Haynes, McKinnon's great-niece, whose DNA matched McKinnon's.

Last week, they were all there at the burial: Maureen Haynes and her cousin, Anne Johnson; Jim Halliday; Fabien Demeusere and even Laurel Clegg, who clutched half a dozen poppies and said she had come to bury 'my boys'.

'I've been working on this case for years and it's really easy to forget it is not just a pile of paper on your desk,' she said. 'These are people who were sons and husbands. All the scientists wanted these men to have a name when they went in the ground.

'Now I work in a coroner's office talking to relatives whose loved ones died last week. What is so surprising and moving is that, talking to these families, there is no difference: their emotions are the same.'

After laying her wreath, Anne Johnson, 73, who used to teach maths in Dorset, said she certainly 'felt a link' with McKinnon, her great-uncle. Her daughter, Andrea, wore a scarf in McKinnon tartan for the burial.

Jim Halliday also laid a wreath. On his way to the service from Canada, he had made a pilgrimage to France Lynch, stopping at the cottage where Halliday was born. 'I felt like he had just died yesterday,' he said after the service. 'I never knew where his body was, nobody did, and all of a sudden you are burying somebody who is your uncle. It is such a wonderful thing to happen.'

On the other side of the low stone wall stood two more men wearing sombre suits. Philip Linnell, 55, and Martin Hemsley, 50, are both great-nephews of Major Henry Linnell, who commanded the 78th Battalion and died at Hallu that day. His remains, too, have never been recovered.

They only met three weeks ago, when Mr Linnell stumbled across information about the reburial on the internet and decided to trace any other ancestors. They drove over from London together, after stopping off at the house in Hackney where Major Linnell was born.

The Canadian authorities think it unlikely, but both like to think their forebear could be one of the three unidentified soldiers reburied here.

In any case, Mr Hemsley said they could not miss the reburial of eight men who had served him. 'They must have been as close as anything,' he said. 'How could we not come and pay our respects?'

There was time for one final surprise. As the descendants shared stories about their ancestors at a reception in the village hall, Ms Clegg suddenly asked for silence and called Jim Halliday to her side.

Then she handed him his uncle's locket. Inside was his sweetheart's name, written in pencil on a piece of cardboard, and two locks of her hair.

A century ago, Sidney Halliday left his home, eventually losing his life and his name. This weekend, his nephew is flying back to that same farmland, Sidney's name restored and his locket safely in his pocket. 'It is part of the family now,' he said.

CBC News- Canada