With Armistice Day today and Remembrance Sunday approaching, it is important to consider the effects and consequences of World War One.
War graves in Belgium
Over eight million men were killed in the conflict, 37 million wounded, and nowhere was the slaughter greater than on the Somme battlefield, in a battle which began on 1 July 1916 and went on to last for several months.
The opening day of the offensive saw no fewer than 20,000 British dead, the worst casualty figures ever endured by the British Army in a single day.
Nearly a mile wide and over a mile deep, Mametz was made up of thick trees and dense undergrowth. The wood was heavily fortified with machine guns, trenches and mortars and was defended by the well-trained and elite Lehr Regiment of Prussian Guards.
The 38th Division was comprised of soldiers from several Welsh regiments, including the Royal Welch Fusiliers and the Welsh Regiment, young men who had been urged to enlist by the rhetoric of David Lloyd George and the thought of exciting adventures.
They were amateur soldiers, full of enthusiasm and courage but, like many of Kitchener's New Army who fought on the Somme, they were poorly trained, ill-equipped and badly hampered by the tactics of their commanders.
The Battle of Mametz Wood began on 7 July 1916. The wood was intended - by the generals, at least - to be taken in a matter of hours. In the event the battle lasted for five days as the Germans fiercely resisted the assaults of the Welsh Division.
On the first day alone over 400 casualties were sustained. Among these were the Tregaskis brothers who originally came from Penarth. They had emigrated to Canada before the war began but, answering the call for volunteers, had returned to join up and fight for Britain.
One of the brothers was shot in the head during the first assault; the other brother went to help him and was also killed. The two men now lie buried in one of the quiet but haunting cemeteries that mark the Somme battlefield.
Over the five days that the battle raged, Mametz Wood was devastated as artillery shells fell continuously on the area. Fighting was furious, with hand to hand combat in many instances, as men battled for every inch and yard of ground. The poet Robert Graves fought in the battle and, having gone back into the wood once the battle was finally over, wrote:
"It was full of dead Prussian Guards, big men, and dead Royal Welch Fusiliers and South Wales Borderers, little men. Not a single tree in the wood remained unbroken."
Casualty figures for the Welsh Division amounted to 46 officers and 556 other ranks killed. When the wounded and those listed as "missing" - men blown to pieces or buried alive by shell blasts - were counted the total number of casualties was 3,993. And that is not counting the numbers of German dead which must have been somewhat similar.
Yet despite achieving their objectives and driving the Germans back to their second line of defences, the Welsh Division was never given real recognition for its achievement. There was even an accusation that the division had failed to advance with enough spirit - in other words the men were accused of cowardice.
It was an accusation that was later withdrawn but it left a sour taste in the mouths of many of the men who had seen comrades killed and mutilated in one of the most bloody battles of the whole war.
World War One was a time of such horror and ferociousness that it has never quite left the consciousness of historians and writers.
When men, like those of the Welsh Division, flocked to join up in the days and weeks after the declaration of war they had no concept of what was waiting for them on the killing fields of Flanders and the Somme. They confidently expected a quick victory - "Home by Christmas," they quipped.
Now there is no one left alive who actually fought in the war and it will not be long before the whole terrible conflict is consigned just to history books. The horror of the trenches and surviving the carnage of a battle like Mametz Wood will become simply dry facts, studied in schools and colleges.
The essential message of the war - that such slaughter must never be allowed to happen again - will be forgotten. That is why Armistice Day and Remembrance Sunday remain important moments in the calendar.
Read Phil Carradice's blog on soldiers' poetry of World War One.