Day one of the Somme saw 60,000 British casualties including 20,000 dead
The Battle of the Somme, which began in early July 1916, has come to symbolise the horror and futility of war, as Fergal Keane reflects on a visit to the battlefield.
On the other side of the wood, the fighters soared and looped in a bright blue sky.
I was standing in a cornfield and thought of how, in another time, that sound would have sent me running in terror for any cover I could find.
But I was not in south Lebanon now, or Iraq or Afghanistan. When the French military jets, practising for an air show, eventually wheeled away, the song of a skylark filled the air.
The soldier poet, Isaac Rosenberg, heard that song. Rosenberg, whose family had fled anti-Jewish attacks in Eastern Europe, was serving on the Somme with the British army.
He described the birdsong "showering men's upturned faces" - a small miracle in the dawn as he returned from a night patrol in No Man's Land. His poetic genius was stilled by a German bullet later in the war.
We walked from the British lines to the German, across the ground where the doomed thousands had advanced on that July morning 94 years ago, into the flying lead of German guns that had withstood the most intense artillery bombardment in the history of the British army.
Between July and November 1916, more than a million men became casualties of war in these fields.
Many WWI soldiers were buried in war graves built close to the sites of battle
Today the chalky soil is planted with barley and corn, and when a breeze rises and brushes the stems and ripples across the fields, it seems the gentlest landscape in the world.
I thought of the lines of Basho, the great Japanese poet of the 17th Century, who, coming across an old battlefield littered with warrior's rusting armour, wrote: "Summer grasses. All that is left of the dreams of soldiers."
We walked up through the fields, across No Man's Land, through a small clump of trees and hedges to the great crater of Lochnagar.
Here, two minutes before the advance began, British sappers had detonated a series of huge mines under the German positions.
It is the memory of the individual that strikes most forcefully at the Somme
Even to someone used to the physical devastation of war the first sight of Lochnagar is heart-stopping. The crater is 300ft (91m) in width and 90ft (27m) deep.
In these fields, and further north into Flanders, was laid the pattern for war in the modern age. An epoch of machines and inventions, from the tank to poison gas, to aircraft, to atomic bombs.
It stretched out from here into a future where machines would riot across the earth, and the capacity to kill and maim would be limitless.
But it is the memory of the individual that strikes most forcefully at the Somme.
A colleague walking ahead of me across a newly-planted field suddenly knelt down and picked up what looked to me like a small stone. It was a button from the tunic of a French infantryman. One late fragment of all that had been lost here.
That sense of war as the country of the individual soldier has been with me as an unshakeable presence in these last few weeks. Soon after coming back from the Somme I went to Scotland to speak at a book festival.
The countless poppies of Flanders have come to symbolise casualties of war
I was talking about a long forgotten battle in India in which a small force of British and Indian troops had endured a terrible siege at the hands of a much larger Japanese force.
When it came time for the audience to ask questions, an old man in a wheelchair raised his hand.
"My name is Angus Taylor," he said. "And I was there." He told his story of a fighting march across jungled hills, against a pitiless enemy.
Angus Taylor described coming on the bodies of comrades who had been laughing and joking with him just a few hours before. There was no hint of bravado in his speech, or self pity.
He was a modest man, one of those many quiet fathers who had come home from war and found a job, made a home for his children, and spoke little of the places he had been or the things he had seen.
Afterwards we had a chance to speak alone. Angus brought out his photographs of the war. Among them were two which he kept in a little black wallet.
"I found that on the body of a dead Japanese," he said.
There were two photographs in the dead man's wallet. One showed a woman posing shyly for the camera, alluring in her traditional dress, and the other a child, the couple's daughter, plump and smiling, leaning against the outside wall of the family home.
The soldier would have taken these photographs before he left for the war and kept them with him until the end. For 60 years they had lain among another man's memories. In such a way does war bind the living and the dead.
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