More than half a million British and Empire forces had already been killed in the Great War by the time the Commonwealth War Graves Commission was established to keep an official record of the fallen in May 1917.
Nearly half a million more deaths would follow between then and Armistice Day as the bloodshed of World War I continued on a scale never previously witnessed.
And when Europe slid back into conflict in 1939, the Commission was once again needed to record the fallen.
World War II involved the British public much more directly than the Great War, so the CWGC began to record the names of civilians killed in the Blitz as well as fallen soldiers.
At the request of Winston Churchill, the civilian records were kept secret because the wartime prime minister feared it would hit morale on the home front.
Establishing and maintaining the records from both world wars would be an enormous task even today - but in the first half of the 20th century many of the details were written by hand, making referencing and updating records an almost unimaginably difficult undertaking.
The Commission was able to draw on its experience of 20 years earlier for World War 2 and began the task of keeping a record of the dead while the conflict carried on.
But they had to contend with Hitler's advance - with some of their staff even evacuated from mainland Europe at Dunkirk in 1940, shoulder-to-shoulder with Allied troops.
Staff would identify bodies, check and re-check details and then clerks would type up the finished records.
It was only by the mid-1960s that the bulk of the job of creating the records was complete.
Now the CWGC is making its archive of digitised World War 2 records available to the public to coincide with the 70th anniversary of Victory in Japan (VJ) Day on August 15.
The Japanese surrender marked the end of the most widespread war the world had ever known.
For the first time the public are able to see the meticulous process of recording the scale of the loss suffered by Britain and other countries, including Ireland and India.
The records of some German soldiers buried at sites maintained by the Commission can also be viewed.
The digitised records include incredible levels of detail such as headstone inscriptions and, in some cases, the journeys undertaken by fallen soldiers to their final resting place.
The documents reveal, for example, that Corporal Ronald Francis Shaw, of the 84th Squadron of the Royal Air Force, was killed aged 25, likely as a result of the atomic bomb dropped on Nagasaki on August 9, 1945.
And they show that as many as 20 Allied prisoners of war, including Dutch and American troops, could also have died alongside tens of thousands of Japanese who perished on the day of the attack.
You can also view the records of 16-year-old Private Jack Banks, thought to be the youngest British soldier to die in World War II. Serving with the Durham Light Infantry, he took part in the Allied invasion of Nazi-occupied France, codenamed Operation Overlord, and was killed fighting to liberate the town of Caen in Normandy.
Andrew Fetherston, the CWGC's Archivist and Records Manager, said: "The release of our Second World War archive online opens a new avenue for members of the public to investigate and remember the individuals we commemorate.
"With the addition of these documents, alongside records relating to non-Commonwealth casualties buried in various sites around the world, it will now be possible, for the first time, to see the original records of all 1.7 million individuals the Commission commemorates.
"The archive will greatly enhance the experience of searching the CWGC's records and will mean that millions of people across the Commonwealth could discover more about their relatives who fought and died during the Second World War."