On the anniversary of the end of the First World War, even photographs cannot speak of our true history

Francois Bost, a war photographer, is being celebrated in a new exhibition in Dublin. He was unable to capture grim reality, but inspired the art of others

A hitherto unpublished photograph from the exhibition of the French army in the First World War (Francois Bost)

Now here are some weird historical connections…

I celebrated the 100th anniversary of 2nd Lieutenant Bill Fisk’s journey from England to the Somme in August 1918, by pushing open the 18th-century wooden door of 3 Great Denmark Street in Dublin this week, and entering the First World War.

I promised some years ago to leave my dad out of future columns – a veteran of the Somme, he was spared the first blood-soaked battle in 1916 by Padraig Pearse, whose rebellion in Dublin forced the Cheshire Regiment to send my father to Ireland instead of France – and anyway, this is the story of two brave French soldiers, the famous poilus who fought alongside Bill and tens of thousands of other British soldiers.

The address in Dublin, wherein I held in my own hands the original diary of Francis Regeard (killed in action 1917) and the equally original and never-published photographs of French war photographer Francois Bost, has a certain grim significance. For this was once the home of John Toler, 1st Earl of Norbury, Ireland’s “hanging judge” who in 1803 infamously ordered the hanging, drawing and quartering of that great Irish nationalist Robert Emmet.

The heavy door which I pushed open in Great Denmark Street was the earl’s front door, the original iron bolt – and much is indeed original in this story – now welded to the wood by thick rust and centuries of paint.

Here dwelt, then, an Anglo-Irishman every bit as ruthless as General John Maxwell, the British governor general who executed Pearse, who in turn had probably saved my dad’s life by keeping him from the Somme on 1 July 1916, when 20,000 British and Irish soldiers were slaughtered in 24 hours.

But walk only 10 metres inside Norbury’s old Dublin front door and there, on the left-hand wall, is the spidery outline of a British bi-plane, wheeling in the sky, high over the very same Somme to which my father was eventually dispatched. For the house now includes an art gallery owned by Frenchman Olivier Cornet whose great-grand-uncle Francois Bost took this astonishing photograph over the battlefield in 1916. Cornet almost touches the surface of the actual photo as he points to the roundels on the wings of the minuscule Nieuport bi-plane fighter.

“The Nieuport was a French machine and I thought the roundels were French,” he says, “but the shading of them suggests they are British and that this plane belonged to the Royal Flying Corps.”

So what was he doing, this lone Brit, soaring above the clouds of France in 1916, in so fragile an image that I thought it might be a sketch until I realised that Francois Bost had taken the photograph, presumably from a French aircraft of the Armee de l’Air? Another picture shows the same Nieuport climbing sharply against the clouds. The Brit, I suspect, was showing off to his French counterpart.

For Francois Bost was an official war photographer and his work is now part of this unprecedented little exhibition (closing on 24 August) and, if you come to Dublin and if you ask gently, his descendant Olivier Cornet will let you hold and turn the pages of Francois’ album of real and (yes again) original photographs.

This is first-definition material. You can stare at the broken trenches and the French troops marching up to the line near Peronne, their huge artillery pieces towed by nags, a cloud of dust –shellfire? – hanging in the air behind them. Francois’ camera looks down on the frosted fields of the Somme in winter, smallpoxed with hundreds of shell holes, but the remains of canals and railway lines and fields are still etched beneath the square box trenches. A line of what must be soldiers – probably French, but perhaps German – far below, can be seen tramping through this chaos.

In other snapshots, there are gun limbers and an early French tank, its gunners sitting on top wearing berets. One picture shows French troops talking to a dark-uniformed military photographer with a box camera hanging round his neck – a colleague of Bost or maybe Bost himself, taken by another soldier – while another photograph shows mountains of shells piled beside a line of railway wagons.

What Bost could not photograph was the ultimate reality: the French dead of the First World War. There were almost a million and a half of them, killed at an average rate of 900 a day, one in 20 of the French population. No wonder Bost, a conservative Catholic who survived the war, could only take pictures of the German dead (for whom the scorecard by November 1918 reached just over two million). But this missing and final component of the war is taken up in the exhibition by infantryman Francis Regeard.

He was killed in battle on the Somme on 5 November 1916, and he was the great-grand-uncle of French artist Leo Regeard, by chance a friend of Cornet – both now residents of Dublin – and the two men developed the exhibition together.

Francis Regeard kept a notebook in astonishingly graceful handwriting, for a man in the French trenches of the Somme, and drew details of guns, munition parts, even a sketch of a young woman. Using Francis Bost’s photographs for both inspiration and accuracy, Leo (with the help of his historian father) produced a stunning comic book account of Francis Regeard’s life and death.

It is an imaginative, fearful portrayal of sadness and distress, brief patriotism, cynicism and finally – in alarming detail – death on the battlefield.

Leo, or Leyho as he calls himself as an artist, imagines that the sketch of the girl in Francis’ notebook is called Suzanne – in the comic book she is his lover, their marriage only prevented by her middle class family – and the soldiers, treated as dogs by their officers, actually turn, in Leo’s comic book, into yelping and rabid dogs, wearing their respective blue and field-grey uniforms and steel helmets. Hence the title of the book, Chiens Bleus, Chiens Gris.

In the final scenes, Francis is shot in the chest, and immediately returns from dog-image to a simple, bespectacled, dying soldier, blood drooling from his mouth. Throughout the comic book, we have seen his sister Henriette arranging for her bother’s exhumation from a war cemetery to his own village graveyard at Becherel in Brittany. When asked by the French army to identify her brother’s corpse, Henriette is given Francis’ notebook, the very same document lying now in the exhibition case in Dublin.

And – here we return to the comic book – she stands at the final graveside for Francis’ military funeral in 1921 and, filled with despair and anger, she horrifies the mayor and local authorities by accusing them of destroying the values in which Francis believed.

He had been a schoolteacher, she says, who wanted to “impress upon young people the values which allow humanity to live together. Alas, this war – provoked by others but experienced by my brother – has become the sepulchre of all these values.”

We do not know if Henriette spoke such words, but we feel that she should have done. Speak not, perhaps, of Brexit here. There is a real photo-portrait of Francis in the book, on leave just before his death and wearing his beret and tall boots, standing next to him the real Henriette in a pale blouse, her dark hair in a double bun. And among the Regeard family papers, Leo’s father found a letter about “Suzanne”. She did exist. It was her real name. There was an affair. Her family did, sadly, end their engagement. Francis was too poor, they decided, to marry Suzanne.

So he went back to the trenches to die for France. Pearse died for Ireland. Bill was ready to die for England and, I suppose, for France. But like Francois, he survived into old age.

So did the Judge Jeffreys of Ireland, I reflected to Olivier as I left his gallery. The good earl died in 1831, in his 86th year – after a lifetime of sleeping in court and imbibing fine claret – in his bedroom, just above us.