SOME time just after Christmas, 1914, two young York soldiers of the Yorkshire Regiment serving with the British Expeditionary Force sat down to compose a letter to the Lord Mayor of York, JB Morrell, and his Sheriff, Oscar Rowntree. Private Edmund Skelton was 35 or 36; his friend Private Thomas Porritt in his late 20s.

Just before Christmas, the pair had each received a small steel tin packed with chocolates as a personal gift from the Lord Mayor and Sheriff. 'Best wishes for a Happy Christmas and a bright New Year to all York men who are serving their King and Country', said the message inscribed on the tin's lid.

You can only imagine the envy of Edmund and Thomas's fellow soldiers as they opened their tins and the rich aroma of chocolate stole out. Their genuine gratitude leaps off the page - not just for the chocolate itself, but for the mere fact that they had been remembered.

"Such a gift from 'the old city' at this time, is another proof that we are not forgotten by the people at home," the letter read.

"I can assure you that the gifts are not only appreciated by us now, but that the boxes will be treasured by us (or ours) long after this war is over."

So they would be: but sadly, neither Edmund nor Thomas would be alive to see it. Private Skelton, a former baker who stood just five foot five inches tall, was killed on the first day of the Battle of Loos in North East France on September 25, 1915 - less than a year after receiving that gift of chocolate. His friend Private Porritt was killed at the Somme the following year.

The two men were among hundreds of young York soldiers who were sent tins of chocolate by the Lord Mayor and Sheriff that Christmas of 1914. Hundreds replied - and 255 of their letters still survive in the city archives.

Plenty of research has been done on the letters. In 2013, they featured in a new play, Blood + Chocolate, telling the stories of the men and women of York's chocolate factories during the war. Exhibitions have also appeared about them in local museums.

But when local historian Rosemary Anderson, recently arrived in North Yorkshire and looking for a good project to get stuck into, first became interested in the letters in 2016, she found to her surprise that no definitive book appeared to have been written.

Rosemary, a former dyslexia specialist teacher, determined to put that right.

Her immediate aim was to try to find out how many of the young men who received those boxes of chocolates survived the war. That was the challenge set her by York archivist Laura Yeoman after Rosemary attended a talk Laura gave on the letters at Explore York.

But as she began to trawl through the index of the letters, Rosemary found herself getting drawn in more and more.

Many of the men had only included minimal personal details when they wrote their letters of thanks, she says. So she began to comb through digital copies of the original letters themselves to search for more clues about their lives.

"And as I worked through the set of 255 letters it became increasingly clear that they were a treasure trove of fascinating information about the lives and wartime experiences of the soldiers and sailors who wrote them," she says.

Rosemary felt compelled to find out more about the men - not just those who died, but also those who survived - by by trawling through official records from the time.

The result is a new book - The Chocolate Letters: York Men and the Great War - which has just been published in time for Remembrance Day.

Reading the letters, one of the things that most struck Rosemary was the sense of optimism felt by many of the men that the war in which they were engaged was being fought for a good cause - and that it would soon be over.

She devotes an entire chapter of her book to analysing the emotion expressed by the soldiers in their letters. One wrote of 'undergoing the hardships and fatigue of active service for a good cause'. Another - a Captain FB Archer - wrote that 'we hope to get a move on things before long, and to let the Huns know that they are up against more than a contemptible little army' - a scathing reference to Kaiser Wilhelm II's reputed derisory description of the British Armed Forces.

Self-deprecating British humour made its appearance in the letters more than once. Private Joseph Farrell Calpin wrote: "You will kindly excuse the pencil marks as in barracks pens and ink are, to all appearances, completely extinct."

There was also a great deal of pride in their native city on show. Trooper F Busby of the East Yorkshire Yeomanry wrote of the 'dear old ancient and honourable city to which I am so proud to belong'.

Inevitably, however, the most moving letters come from those, such as Privates Skelton and Porritt, who did not survive the war.

In answer to Laura Yeoman's challenge, Rosemary was able to identify at least 20 of the men who received those tins of chocolate at Christmas 1914 who did not survive the war. "I'm sure there are more," she says.

The story of those 20 is told in the book's final chapter, 'PAX - In Memory of York Men'.

Here are a few memories from that chapter...

Letter from Warrant Officer/ Gunner Charles Catley of the Royal Navy

"Dear Sir, I am writing to thank you and the City of York for the Xmas present you were good enough to send me.

"I appreciate the kindly thought very much. It is a great honour, as well as a great responsibility, to help to represent a city holding the traditions which York holds at a time like this."

Gunner Catley, whose family lived on New Walk Terrace, died at sea during the Battle of Jutland in May 1915, aged 38.

Letter from Private Sidney Charles Gibson, West Yorkshire Regiment

"Dear sir, Lance Corporal Gibson and Private J Smith, York, both wish to sincerely thank The Lord Mayor & the Sheriff, for their kindness in presenting us both with one of your souveniour (sic) boxes of chocolates. I am also pleased to say my comrades were glad to enjoy it with me."

Lance Corporal Gibson, a grocer's apprentice from Scarcroft Road, was killed in action at the Somme on July 1, 1916. He was 23.

Letter from Major Richard Digby Johnson, Royal Dublin Fusiliers

"My dear Lord Mayor, I have just received the box of chocolates in the trenches. Please accept my very best thanks. I need hardly tell you how pleased I am to receive it. The one thing we all look forward to here is the mails - and feel we owe a great deal to all those at home who have done so much for our comfort."

Major Johnson, whose family lived in a large house with servants in Bootham, was killed in action near Ypres on May 24, 1915, just three months after writing his letter. He was 38.

The Chocolate Letters: York Men and the Great War by Rosemary Anderson is printed by York Publishing Services, priced £12. It is available from York Explore library; the York Minster shop; the York Army Museum; or from