World War One: Couple thanks every fallen soldier
In 2012 - like many British couples - Steve and Nancy Binks decided to buy a caravan and head off on a tour of France and Belgium.
But this was no ordinary camping holiday.
Instead, the Binks, from Colwyn Bay, Conwy, were on a mission to visit the grave of every Commonwealth serviceman and woman killed in those countries in World War One - all 750,000 of them.
"We wanted to do something to commemorate the centenary of the Great War, something that no-one else would think of doing," said Steve, 58, a tour guide who has a lifelong passion for World War One.
"First we thought we'd just go and visit every cemetery on the Western Front, but I thought it sounded a bit like trainspotting - just going in, taking photographs to say we've been and then walking away.
"We wanted to do something more inspirational so I thought, why not stop at every headstone, read it and say thank you to the soldier."
With just under 2,000 burial grounds dotted all over France and Belgium, the project is a mammoth undertaking.
Four years in, Steve and Nancy, 56, have visited 766 cemeteries and have said "thank you" 461,012 times.
As well as reading every headstone, they also recite the names on the memorials to the missing; those thousands of soldiers whose final resting places are unknown.
"Most people don't quite understand the level of detail and work that's involved," said Steve.
"Some of the larger cemeteries took six-and-a-half days just to walk the headstones because I make sure I stop, turn and read each one.
"The huge Memorial to the Missing of the Somme in Thiepval has been our biggest challenge so far.
"The sheer scale of trying to read 72,500 names with your neck stretched back, in an arch, with a cold wind blowing - it was impossible to do it in a week or two.
"We had to keep returning to it over a six month period and keep chipping away, saying thank you to every soldier."
Nancy, who has multiple sclerosis (MS), is unable to walk every road in every cemetery.
"I like to sit down and read the cemetery register," she said. "I pick out the brothers, I find out the ages of the men and if they were awarded any medals. It's such interesting reading."
The couple, who split their time between north Wales and the continent, work chronologically - so far they have visited most of the burial grounds that contain casualties from the first three years of the war.
"We still have 450 cemeteries to visit for 1917 - including most of the big Somme burial grounds," said Steve.
"That's going to take us at least 18 months to two years.
"Then we have 800-odd cemeteries for 1918 burials and in that final year, the casualties were the highest for the whole war and because by then it was a war of movement, those cemeteries are quite fragmented so the trip will become quite logistically difficult."
They also keep meticulous records of their trips.
"We have 10 volumes of journals from day one," added Steve. "We write down our thoughts and feelings about the trips, about some of the soldiers we've stumbled across and about some of the cemeteries that no-one has been to from a very long time.
"We take photos of anything that's been left on a headstone and where there's a photo of a soldier on a headstone, we photograph that as well.
"We were in one of the Somme cemeteries from 1915 and there was a letter and a pair of socks left on a grave.
"It was the soldier's last letter home and he'd asked for a pair of socks so someone had left some there for him."
It is perhaps inevitable that some soldiers' graves will attract more interest than others - at Lijssenthoek in Belgium, for example, the most "popular" grave is that of Nellie Spindler, a nurse.
But in the eyes of Steve and Nancy, all servicemen and women are equal.
"We try not to elevate anyone above anyone else, even my own relatives," said Steve, who lost two great uncles in the war.
"A captain or a private - to us, it's irrelevant.
"Every one deserves to be remembered and every one deserves to be thanked."
Unsurprisingly, the pilgrimage - which Steve and Nancy have named "Some Kind Hand" after a famous inscription which appears on several soldiers' headstones - leaves them little time for anything else.
"It's more than an interest," said Steve. "It's more than a passion, even. At the moment, it's our life.
"Some people do think we're a bit mad," added Nancy.
"But I find it therapeutic. When I'm at home, it's all about MS, but when I'm in France or Belgium, I get involved with everything and the MS takes a back seat.
"I'd rather be there, with the soldiers."