A mammoth archive newly available on the internet uncovers in fascinating detail the lives of our great-grandfathers on the front line of the first world war. LAURA DEVLIN opens a window in to the past at the click of a mouse. ancestry.co.uk

Five million British soldiers marched off to the first world war and fought and died in some of the of the most horrifying conditions known to man.

Until now, the unique experiences of each individual - from the terrified teenager to the stiff upper-lipped colonel - have only lived on through their own stories or diaries.

But what of the countless millions that never put pen to paper, never relived the painful memories to their loved ones or died alone and lost on the bloody battlefield?

Incredibly, their distant world that should never be forgotten but could so easily have been lost forever has been opened up to all us at the simple click of a button with millions of army records being placed on an ancestry website.

Anyone who never had the answer to the age-old question "granddad, what did you do in the war?" can now find out, along with descriptions of granddad's appearance as a young man, his performance on the battlefield and any military honours.

While genealogy enthusiasts once had to embark on a determined mission to discover their ancestry by scouring the National Archives in Kew, London, for days on end, lives from the past can be at our fingertips and on our screens within minutes.

Although five million soldiers from England, Scotland, Ireland and Wales fought in the first world war, about 60pc of the service records were destroyed during a German bombing raid on the War Office in September, 1940 - making the remaining documents even more precious.

Known as the W0363 British Army Service Record and W0364 British Army Pension Records, the collections will be released in phases, starting with the early pension records.

These original, surviving records, which cover the military service period of 1914 to 1920, have been conserved and fully indexed by the National Archives and are now available - partly for free - at www.ancestry.co.uk.

Although the collections vary in detail, users will be able to discover key information in both collections, including physical description, regimental number, service history, locations served, date and place of birth, former occupation, next of kin and promotions.

The pension records, which relate to soldiers discharged on account of sickness or injuries sustained during the war, include the medical records relating to the disability for which a pension was granted.

The service records describe the careers of soldiers who completed their service, were killed in action, executed or died of their wounds or disease, and provide full details of their service, and where recorded, death.

Simon Ziviani, of ancestry.co.uk, said the 1.4 million service records alone, which are yet to go online but should be completely available by next year, often constitute 30 to 40 pages of paperwork for each soldier.

"It's a very detailed collection where you can find out about any individual soldier and their performance on the battlefield. It talks about their injuries and gives you an idea of their physical appearance," he said. "It's quite unusual - like a running military service report card."

He added that the success of each search would vary and would often depend on the starting point, but would previously have taken about four days of research at Kew.

"It would depend on how much, say, your great-grandfather had discussions about the war, on his keeping papers, how open he was about what he was actually doing.

"You can go on the website with just a full name and see what you come up with, but many soldiers who were underage changed their names, so their families could not track them down and take them out of the army - so the name you think you know might not be what you discover.

"Thousands disappeared off the face of the earth, died on the battlefield under a false name because they couldn't tell their own parents. It was a huge problem in the first world war.

"So many men said little or nothing about their years of service in the war because they just didn't want to talk about it.

"Now you will be able to look for the details you could not get from your great-grandfather and see him as a young man and see what he saw through his eyes - really interesting, insightful observations - and maybe find a few surprises.

"The physical descriptions are something people would not have got before, but now you can find out what someone looked like long after they died."

The Victorian, military language used in the records is fascinating in itself and almost underplays the atrocities described.

"There are lots of different descriptions for bravery - old-fashioned terms - and it's amazing how most put a very positive spin on everything, they thought 'this is my duty and I will not complain'," said Mr Ziviani.

"What we hear from our members who have searched for their ancestors is that people are describing unimaginable experiences in a very literal way."

County archivist John Alban, who works at the National Archive in Norwich, said the online archive proved genealogy was growing in popularity and had become big business over recent years.

A family history-related open event last year attracted almost a thousand visitors to the centre next to County Hall in the space of five hours.

"What the National Archive and the Norfolk Record Office have been doing over the past decade is making files available so that people anywhere in the world can find out what we have here, but what this website has done has made images available of actual documents online so you can read them.

"We would like to do the same thing, but it is a long process that would take many, many years.

"Sixty-seven per cent of our visitors last year were tracing their family history and when you have big and very high profile programmes like the BBC's Who Do You Think You Are? it gives it even more appeal.

"If your ancestor was a soldier in the first world war, this is going to be a fantastic resource for you, and in general family history has become big business, and many people are interested in it now.

"People really want to know 'where have I come from?'."

It seems almost ironic - and a measure of how our lives contrast with theirs - that we can dip into each individual soldier's world of hardship, loss and suffering with such ease.

These words have existed for almost a century and remarkably survived the atrocities of another war to have us dust them down and breathe new life into thousands of fallen men from the comfort of our own homes.

ancestry.co.uk