SATURDAY, July 1, 1916, was the most devastating single day in the history of the British Army.

On the first day of what became known as the Battle of Somme, British forces suffered 57,470 casualties, 19,240 of them killed.

Over the next five months, more than a million men died on all sides as the Allies and German troops fought a battle of attrition over a 15-mile front.

The conflict was so brutal the landscape in northern France is still pitted and pockmarked with its trenches and shell holes.

And, like the Nazca Lines in Peru, the full, sobering picture of destruction is only revealed from the air, as these remarkable images show.

The photographs are the work of Faringdon photojournalist Michael St Maur Sheil, who has spent eight years trying to capture one of humanity's darkest hours in a new light.

Born in Oxford and raised in Brackley, Mr Sheil read Geography at St Edmund Hall, Oxford University.

In the early 1970's he began his life as a photojournalist by covering The Troubles in Northern Ireland.

He became associated with New York picture agency Black Star, and began a 30-year career in photojournalism spanning 60 countries and working for clients from ABC-TV and the BBC to British Red Cross and National Geographic.

But it is this project, the product of nearly a decade of visits to northern Europe, innumerable shots and countless hours of editing, which he hopes will be his legacy.

The 69-year-old, who lives in Buckland near Faringdon, with wife Janet and Greyhound Gonzo, said: "This collection represents a legacy which I hope will create a gateway to the battlefields themselves, thus encouraging people to visit these historic landscapes during the centennial period and so create awareness and understanding of the events and historical implications of the First World War."

The photographic collection, entitled Fields of Battle – Lands of Peace 14-18, has already been exhibited at the Jardins du Luxembourg in Paris, The Royal Parks in St James’s Park, London, and Notthingham City Centre, all in 2014. It was also shown in Istanbul city centre in 2015.

Now, the exhibition is returning to London and the courtyard of the City of London Guildhall between June 1 and July 3, including the 100th anniversary, to the day, of the beginning of the Battle of the Somme.

Mr Shiel explained: "Some 3,500 of those killed on that first day of battle were volunteers from amongst workers in the City of London and surrounds.

"This exhibition has been given the unique opportunity to assist in commemorating the brave men who left the City of London to fight at the Battle of the Somme."

The photographs, mounted on large waterproof boards, will be free to marvel at, but the project has not been free to run.

In order to fund his ongoing work, Mr Shiel helped set up a charitable trust which is now charged with raising a considerable amount to stage the exhibition.

Trustees are only able to achieve this by securing sponsorship, grants and through the generosity of the public.

Find out more at fieldsofbattle1418.org