By Richard Allen Greene and Megan Lane
From hand-written letters from the American civil war to e-mails from Afghanistan and Iraq, letters written during conflicts give great insight into life on the front lines - history, as recorded by soldiers and civilians.
As war becomes ever more hi-tech, fewer and fewer people will have first-hand experience of a life lived on the front lines. The emotions experienced run the gamut from fear to excitement and even hilarity - and it is these emotions that are detailed in that most personal of missives, the letter to a loved one.
These intimate messages are increasingly recognised as just as important a source of information as weighty research and official documents.
And a new book, Behind the Lines, by US archivist Andrew Carroll, brings together correspondence as old as hand-written letters from the American Revolution and as fresh as e-mails from Baghdad.
The way these are written are very much of their time, but the events and emotions experienced are universal. Here, a young American soldier describes tracking down German soldiers in France during World War Two.
"We ran into three Jerries in the farmyard, one of whom tried to hide in a half-filled rain barrel, of all places. I'll never forget the neat triangle of holes Joe's tommy gun put in that barrel!"
His triumph quickly gives way to more complicated emotions.
"I was almost hypnotised as I watched the water change gradually pink and then red as it spouted out the oaken bullet holes.
As we started off across the fields I glanced back at the rain barrel.... A large rooster, which had disappeared in a flurry of feathers such a short time ago, now crowed defiantly at the world."
This letter captures the ambivalence many soldiers past and present feel, says Mr Carroll. "These guys are not gung-ho. To take a human life is an extraordinary thing."
Living so close to death means a struggle with conflicting needs in messages home. "There is the self-censorship of not wanting to worry people on the home front - not wanting to express the horror - but needing the cathartic experience."
While many letters carry words of love and reassurance, few completely excise the horrors of war.
"Do they die as you see them in the movies? I do not think so. Young men shaking from nervous exhaustion and crying like babies. Strong men they are, or were, who did not or will not have the chance, ever, to live normal lives."
US Major Oscar Mitchell, 15 April 1944
Soldiers throughout history have had to contend with official censorship as well. During World War One, the Americans distributed mass Christmas cards with pre-printed statements such as "I am well" or "I have been admitted to hospital" to avoid giving away information useful to the enemy.
That same war, a British soldier wrote a tongue-in-check pre-formatted love letter, which poked fun at the censors and revealed the cynicism many felt about the war:
"My dear/dearest/darling, I can't write much today as I am very overworked/busy/tired/lazy.
We/The Huns put up a bit of a show last night/yesterday with(out) complete/tolerable/any success. I am suffering from a slight/severe wound/shock/shell-shock.
How are the poultry including cows/potatoes/children getting on?
________________________ (Insert here protestations of affection - NOT TO EXCEED 10 WORDS)
Ever _____ (State what ever) xxxxxxxxxxxxxx"
Numerous letters show how soldiers manage to get sensitive news through to their families.
One Gulf War soldier's seemingly casual remark "The flies are huge!" is a coded message to his brother that an attack is imminent. His apparently cheery letter passed the censors and kept his parents from worrying, while letting his brother know he would soon be in great danger.
And amid the horror and the fear, more than one soldier has invoked the censors to disguise his own laziness.
"Dear Dad and Carmilita, I'm OK, days fly by here in _____________. Well maybe it can be all again soon. I'm praying for it. Write soon. Nothing like getting a letter from home. Here on __________
Love, Bill. PS: They may censor this letter."
This letter, written by Arkansas farmer William Kyzer during World War Two, arrived with a huge hole in the middle, cut out by the man himself because he hated writing.
It is letters such as this which keep Mr Carroll going. "Every time I think I have exhausted a subject, someone gives me a remarkable letter. It's a labour of love and something that's going to keep going for a long time."
Rod Suddaby, for one, is pleased to hear that. The keeper of the department of documents at London's Imperial War Museum says the discovery of each new letter adds to historians' understanding of war.
"When something major happens, everyone remembers different little bits of it. New personal testimony emerging about conflicts is always likely to be of interest," he says.
"I hope [such collections] help make people aware that a great-uncle's letters kept in the attic may be of interest to more than just the immediate family."