The story of two British soldiers gunned down by German snipers on December 25, 1914 during the famous Christmas Day truce has been revealed for the first time since the exchange 100 years ago.

While gestures of goodwill spread along the Western Front, the festivities stopped half-a-mile short of where Private Percy Huggins and Sergeant Tom Gregory were on duty in Rue De Bois, France.

The historic ceasefire, which saw men from both sides exchange seasonal greetings and play games of football during the First World War, was shattered by the sound of a sniper's rifle.

Private Percy Huggins, left, and Sergeant Tom Gregory, right, were both killed on Christmas Day by German snipers - the same day the famous 'Christmas truce' was declared along the Western Front

Pte Huggins, 23, from the Hertfordshire regiment's D Company, was on sentry duty at a forward listening post just 20 yards from the enemy when he was killed with a single bullet to the head.

The shooting enraged his platoon Sergeant Gregory, who demanded he take his place and immediately set about scanning the frost-covered ground before taking the sniper out with a shot.

Then as the experienced soldier continued scouring enemy lines he spotted another sniper - but the German marksmen had seen Sgt Gregory, 36, first and in a split-section action shot him dead.

The two British men were among the 149 Commonwealth servicemen who lost their lives on December 25, 1914, although many of those died of previously-inflicted wounds.

Their story has remained untold, overshadowed by tales of the peaceful Christmas morning shared from both sides of the trenches which has now been retold in a Christmas advert by Sainsburys this year.

But their plight has now come to light after the family of Pte Huggins released his letters from the trenches to the Herts at War project, an exhibition to mark the centenary of the outbreak of war.

This is the last letter Private Percy Huggins sent to his mother Agnes from the trenches in December 1914

It was after his family released the letters as part of the centenary that the pair's story has been widely told

The letters prompted researcher Dan Hill to look into the military records and regimental diaries, revealing the full tragic tale.

He said: 'There is no doubt that a truce of sorts took place in multiple points along the line of trenches forming in France and Belgium.

'These men did shake hands and exchange gifts and wished each other a Merry Christmas.

'Less than a mile to the north of the Rue De Bois, we know the men of the 1st North Staffordshire Regiment took part in a truce and one also seems to have taken place to the south as well.

'Many men used the pause in fighting as a time to collect and bury the dead that lay about in No Man's land.

Gravestones for Private Huggins (left) and Sergeant Gregory (right) which stand in Le Touret, France

Le Touret cemetery in France where Huggins an Gregory are buried, after they were shot by German snipers

This is the original grave of Private Percy Huggins in France. He was stationed just miles from where the famous Christmas truce was being held on the Western Front

This map shows the area where the two soldiers were shot by snipers (circled). They were two of the 149 Commonwealth soldiers to die on Christmas Day

'The truce probably bypassed the Hertfordshire Regiment because they were with the Guards Brigade who were incredibly professional and were highly unlikely to have fraternised.

'The story of Percy and Tom's tragic demise on that day serves to highlight that December 25, 1914, was just another day on the Western Front for some.

'To think that Mrs Huggins, Mrs Gregory and the mother of one German soldier enjoyed their Christmas at home unaware at that time of what had befallen their sons.'

Sgt Gregory, from Watford and a father-of-seven, was a veteran of the Boer War and became a postman before he re-joined the army in 1914.

Pte Huggins worked in his family's upholstery business before he joined the army (he is pictured outside)

Pte Huggins pictured with his mother Agnes as a baby. His mother did not hear about his death until January

His wife had just given birth to their seventh child when he was killed and she named their daughter Lille after the place where he died.

Pte Huggins, from Ware in Hertfordshire, worked in his family's upholstery business before he joined the Hertfordshire Regiment, one of the first Territorial Army units to be called up to the regular army in the First World War.

In November 1914 the men joined up with the illustrious Guards Brigade and sailed to France and were soon in action at the first Battle of Ypres.

They then left frontline duties for a month's rest before returning to the trenches on the evening of Christmas Eve.

Soon afterwards Pte Huggins wrote his last, poignant letter home to his mother, Agnes, a widow bringing up seven children by herself back in England.

He thanked her for sending him a Christmas pudding which he explained he would have to eat cold but was still very much looking forward to it.

A newspaper reported the shocking news that the pair had been killed on Christmas Day, also nodding towards the 'Christmas Truce' of 1914

Private Percy Huggin's obituary in a local newspaper notes that he had gone to France in November and was killed in action near Festubert on Christmas Day after being shot through the head by a sniper

Clearly missing his family, he wrote: 'I know you all must miss me and no doubt can to some extent realise what my feelings are for I cannot express them.

'I long for the day when this terrible conflict will be ended. You consider war a terrible thing but imagination cannot reach far enough for the horrors of warfare that can be seen on the battlefield are indescribable and I pray this may be the last war that will ever be.'

He explained he was proud to serve his King and country, adding: 'I can only hope by the grace of God to acquit myself honourably and be permitted to return to all the dear ones in safety.

An image of the Hertfordshire Battalion, which has been colourised for the HertsAtWar exhibition

Soldiers from the 1st Battalion Hertfordshire Regiment, taken around August 1914, upon the outbreak of war

Pte Huggins and Sgt Gregory are not pictured but these soldiers were part of their battalion during the war

'I have already asked, dear mum, that you will spend as happy a Xmas as possible and I will do the same.'

Shortly before dawn on Christmas Day, Corporal Clifford Lane, of H Company Hertfordshire regiment, recalled how the Germans hoisted their lanterns above the trenches and called out to the British as a overture for a temporary truce.

The British responded by shooting at the lights, putting an end to any prospect of a Christmas Day ceasefire - one that could have spared the lives of Pte Huggins and Sgt Gregory.

But as the regiment ate a Christmas breakfast of bread and jam, cheese and a piece of cold bacon, Pte Huggins and Sgt Gregory had already been killed.

It is thought the families of both soldiers received news of their deaths some time in early January and the two men were buried side by side at Le Touret Military Cemetery in Bethune, France.