Fromelles, France (CNN) -- George Collins never knew his father. Mitchell Collins died four months before his son was born, mowed down by machine gun fire during the First World War.
Collins had turned 30 just two days before he died, leaving behind a pregnant wife and young son.
His family never even knew where he was killed, said his grandson, who is himself named Mitchell Collins in honor of his grandfather.
"My father tried to find where the grave was, but he got nothing," the younger Collins told CNN.
"We have only one photograph that we know of, so it's always been very precious to us," Collins said. "He was in his uniform, so it must have been just before he was killed."
Collins' grandmother rarely spoke of her husband, he remembered.
"She was proud of him, but that was all we could get out of her," Collins said of his grandmother Mary, who was a widow for nearly 49 years after her husband was killed. "I didn't hear a lot of stories about him."
So he was all the more surprised last year when he opened his local newspaper in Scotland to see his grandfather's name.
A mass grave dating back to World War I had been discovered in France, and Britain's Ministry of Defence was trying to contact the relatives of soldiers still listed as missing in action from the battle.
It turned out Mitchell Collins had died at the Battle of Fromelles -- a brutal, costly assault intended to distract the Germans from the much larger Battle of the Somme to the south.
Thousands of British and Australian soldiers were ordered to charge a well-fortified German line. They were slaughtered.
Some 2,300 died in a single night, and 1,600 were left missing.
Almost 94 years later, the battle remains the single deadliest 24-hour period in Australian military history -- a tactical feint which achieved nothing.
So many died that the British and Australians were not able to recover all their dead. But the Germans who had killed them buried at least some of the bodies in mass graves, it turned out.
Six of those mass graves were finally located in 2008, and in 2009 a massive project began to excavate the graves, identify as many bodies as possible, and bury them in a new, purpose-built cemetery.
That's how Mitchell Collins found his grandfather's name in the paper -- the British and Australian ministries of defense were trying to get DNA samples from relatives of those killed in hopes of identifying the bodies.
So far, about 800 families have come forward, according to Dr. Peter Jones, the DNA consultant for the project.
He said his team is also working on getting samples from the 250 sets of remains, which is proving challenging.
"It's not like DNA that's recovered from a living person," he said. "You expect it to be degraded, and also there is less of it there than in a contemporary sample."
Teeth are proving the best source of genetic material from the remains which lay underground for decades, he added.
"Teeth are self-contained. There's only was one way in, that's through the root. The enamel gets preserved," he said.
Meanwhile, researchers have uncovered about 6,200 personal effects at the mass graves, which will also help identify the bodies, said archeological consultant Margaret Cox.
"The main things that really impressed everyone involved with the project were the personal artifacts -- the little leather heart with a locket of hair sewn into it, the wallet with the return ticket to Perth (Australia) and from Perth to Freemantle," she said.
Efforts to identify the bodies will continue at least until 2014, according to the Commonwealth War Graves Commission, the non-profit group that is leading the project.
The commission commemorates the dead of both world wars from the Commonwealth, the association of nations that used to be part of the British Empire. Founded in 1917, it maintains graves and memorials at 23,000 sites around the world.
The Fromelles cemetery is its first new graveyard in nearly 50 years, spokesman Peter Francis said.
The commission will list as much information as possible on the Fromelles headstones -- a name or a nationality if it can be determined, they said.
If no identification can be made, the headstone will read simply: "Known unto God."
Mitchell Collins would like his grandfather's body to be identified, of course.
But even if it isn't, simply learning where he died "helped us to fill in a bit of our own history," Collins said.
"Knowing that he was killed there is good enough for us," he said. "It's as if he was found."