It was a battle designed to hasten a victory for the Allies in the First World War.
But it ended up as a military disaster and in the ensuing five months of fighting the two sides remained as entrenched as ever in the quagmire of the frontline.
It was, to put it bluntly, a futile and terrible waste of hundreds of thousands of lives.
By the end of that first day the British Fourth Army had suffered 57,470 casualties, including 19,240 men killed – the bloodiest day in the history of the British Army. The French suffered 1,590 casualties and the German Second Army lost 10,000–12,000 men.
Although many people remember the first day of the battle for the appalling British losses, the Battle of the Somme was a series of battles for the British Army in the sector of the Western Front south of Arras and north of the Somme river.
It began on July 1, 1916 after a seven-day artillery bombardment on an unprecedented scale. The battles to win ground from the German Second Army then continued for well over four months before the battle officially ended on November 18.
By then the Allies had won around seven miles of ground at a cost of thousands of casualties killed and wounded. The German defence was stubborn and the German Second Army also suffered heavy casualties by the end of the battle.
July 1 began with a massive infantry assault against the German frontline at 7.30am on a glorious summer’s day.
The main line of assault ran for 25,000 yards, nearly 14 miles, from Maricourt in the south, northwards to Serre, with a diversionary attack at Gommecourt two miles further north.
This attack was by two divisions of the British Third Army but the centre thrust of the British Somme offensive was between Serre and Maricourt villages carried out by 12 divisions in five corps of the British Fourth Army, totalling more than 100,000 men.
Two corps of the French Sixth Army went into the attack astride the Somme river on the British right wing.
But it immediately went horrifically wrong.
The British infantry emerged from their trenches and advanced in extended lines at a slow, steady pace across No Man’s Land.
But they were met by a hail of machine-gun and rifle fire from the surviving German defenders. Accurate German barrages immediately added to the pandemonium as shells engulfed the attackers and wrecked the crowded British assembly trenches. The advancing infantry – and many waiting to attack – suffered enormous casualties.
Within the first hour the German defence inflicted unforeseen heavy casualties to the British attacking force, resulting in the British being unable to reach their objectives for the first day in most parts of the battlefront.
The main problem was the huge British artillery bombardment had failed.
Although the German defences at ground level had been smashed, many of the barbed wire defences remained.
But, more crucially, a series of bunkers and tunnel complexes dug deep under the chalky Somme landscape had escaped serious damage mainly because the Germans had thought ahead.
The battlefield had been reasonably quiet during 1915 which is when they carried out months of intensive construction, building strategically-sited strongpoints and machine-gun positions on high ground and strengthening three lines of defence.
That’s not to say the Germans hadn’t suffered from the week-long barrage. It had caused disruption to the German supply routes and terrified many of the German troops due to its incessant noise and fear of death.
Yet as the British began their advance the German troops who had survived caved-in bunkers carried out their well-rehearsed drill of climbing out from the protection of their deep bunkers to man the smashed-in trenches and, most crucially, their machine gun positions. This had horrendous consequences for most of the men in the British battalions advancing towards them.
On the right wing of the attack two British divisions, the 18th and 30th, did achieve success in passing through the German frontline and reached their objectives. The German defence was disorganised here, low in morale and successfully pushed out of its forward positions.
But the situation for almost all the divisions attacking north of Mametz village turned into a desperate day of disappointment and loss. Small groups did reach some of their objectives beyond the German frontline in places, but the overwhelming loss of thousands of British troops to injury and death within the first hour of the attack limited the possibility of supporting and reinforcing these gains by the end of that fateful day.
The British offensive against the German defensive line on the Somme battlefront was continued in phases from July 2.
This time the task was carried out with limited objectives in a type of operation known as “bite and hold”.
The fighting continued into the following weeks. Weeks then became months.
The ground gained by the British Fourth Army by the end of the fighting of almost five months moved the British frontline to just a few miles further north-east of its original position.
Casualties of injured and dead on both sides amounted to many thousands.
The dreadful irony of the situation would be that within 14 months the ground won at such great cost to the British army in 1916 would be swept back under control of the German Army in the spring offensive of March and April 1918.