When I visited the Western Front for the first time many years ago, the vast cemeteries and gigantic memorials covered with the names of the missing made a big impression on me.

It wasn’t just the scale. It was also the thought that these brave men had been robbed of their personal identities. They still seemed to be standing to attention in the ranks of headstones, so many of which are marked “Known Unto God”, “Soldat Inconnu” or “Unbekannter Soldat.”

The inscription of Victoria Cross winner Samuel Meekosha in a cave network under the village of Naours. (Whispering Walls, Amberley Publishing)

Today, they are seen collectively as a courageous, blighted generation. As you walk along their graves, it is easy to forget that each single one stands for a person who had a story and a dream, and who was deprived of a future that may have changed the world.

Until 2019, I was not aware that there was a realm underneath the trenches where thousands of soldiers had left individual traces, defying their fate in an industrial war in which the individual counted for little.

During a visit to the Somme, I learned of the discovery, or rather rediscovery, of wartime graffiti underneath the village of Naours north of Amiens. I embarked on the most fascinating project I have ever worked on — exploring graffiti ranging from hastily pencilled names to elaborate sculptures hewn into the soft limestone of ancient quarries used as shelters.

Alister Ross of the Australian Imperial Force left an inscription at Naours. He was killed on the Somme. (Whispering Walls, Amberley Publishing)

It is the stories behind the inscriptions that bring this testimony to life. French researchers have led the way in identifying the authors and tracing their fates. In all too many cases, soldiers are known to have been killed within days or weeks of making their mark.  

Now that the conflict has passed out of living memory with the deaths of the last veterans, this graffiti is a priceless record of how soldiers were experiencing and reacting to the war as it was happening.

A bas-relief of Marianne, the French national symbol, in a quarry at Confrécourt. (Whispering Walls, Amberley Publishing)

Whispering Walls, the book I spent three years researching, is meant to shed light on this graffiti, long-forgotten in the blackness of caves, and to introduce the reader to a phenomenon that warrants further research.

As you face the cave walls and taste the chalk dust floating in the torchlight, you get a powerful sense of the moment when the soldiers stood here immortalising themselves.

The inscriptions reflect the variety of cultures that converged on the battlefields. But they illustrate just as clearly what all the combatants had in common: a will to survive, to return to their loved ones, to be remembered, to prove their worth.

Canadian sniper Aleck Ambler’s impressive carvings include the regimental badge of the Royal Highlanders of Canada, alongside its battle honours including the Second Battle of Ypres and the Somme. (Whispering Walls, Amberley Publishing)

Many of the carvings are so intricate that they must have taken hours of concentrated effort, revealing the mental resilience of young people clinging to happiness and hope amid the blood and mud.

Thousands wrote their name, rank, unit, service number and sometimes even their home address. Or they drew portraits of their wife or girlfriend, or the pretty waitress they had seen in a cafe. A beloved horse or dog. A poem. A patriotic slogan. A Christian cross.

Archaeologists have logged some 3,200 inscriptions made by soldiers in caves at Naours. (Whispering Walls, Amberley Publishing)

Soldiers of all nations left graffiti. They drew the insignia of their regiment. They carved four-leafed clovers, the Square and Compasses of their Masonic lodge or symbols of their nation such as Nelson’s Column, Marianne, the Iron Cross, the Canadian Maple Leaf or Buffalo Bill.

It was humbling to venture into these caves, some still strewn with boots, bully beef tins, gas masks and rusted rolls of barbed wire.

There are an estimated 400 sites with significant quantities of First World War inscriptions in northeastern France. I visited over a dozen and was stunned by the beauty of some of the sculptures. But I was particularly moved by simple drawings such as one by a farmer from Ontario, Earl Leroy Lacey, who drew a pig, a horse and a chicken in ink pen that is very faded now.

A lonely ship in a sea of darkness. A carving attributed to an American soldier. (Whispering Walls, Amberley Publishing)

Lacey was thinking of home on the eve of the Battle of Vimy Ridge. He was killed in action almost a year later, in February 1918.

In some quarries I visited, I was able to enlist the help of local guides. In one, I used a spool of string to avoid getting lost. Another turned out to be protected by wild boar.

The photography was challenging because I needed to carry cameras, lenses, lights and tripods along the tunnels and had to work fast to avoid batteries running out. I wanted to present the works as well as possible, not just for the readers but also to do justice to the soldiers who created these works.

The cap badge of the Queens Own Royal West Kent infantry regiment in tunnels under the village of Bouzincourt. (Whispering Walls, Amberley Publishing)

The quarries, dug centuries ago to provide stone for houses and churches, served as refuges in times of war and an air of secrecy surrounds them to this day. Almost every village has one, and the armies used them as hospitals, command headquarters and for accommodation during the war.

A lot of them are out of bounds on private property and dangerous to enter. Some are at risk of collapse due to the use of increasingly heavy farming machinery on the fields above.

Inscription by an American soldier. (Whispering Walls, Amberley Publishing)

Some that are known to contain particularly fine graffiti are under the watchful eye of heritage groups that have installed gates and grilles to keep out looters who have been gouging artworks out of the walls.

In others, I saw some sad examples of modern graffiti spray-painted over wartime inscriptions. Enemy combatants who tried to kill each other for years showed more respect for each other’s creations.

Enemy soldiers respected each other’s traces, as these French and German inscriptions show. (Whispering Walls, Amberley Publishing)

That was what surprised me most. The lack of hatred for the enemy in the inscriptions, and the mutual respect.

You get French and German names written next to each other because quarries would change hands quite a lot. In one cave I saw regimental insignia from British, French and German units chiselled into the rock side by side, as if they were football clubs. “They knew they were going through the same hell,” said one French archaeologist.

I plan to continue exploring this legacy.

David Crossland's book Whispering Walls is available for purchase now.