On 1 July 1916, their armies, relying in part on their colonial troops, launched the largest battle of the Great War in terms of the number of nationalities involved and number of casualties: one million persons wounded, dead or missing.
The Somme became an international space where more than twenty nationalities came to fight or work.

And the internationalization did not come to an end in 1918: it was to continue with the souvenirs brought back by millions of participants and a war memory which remains alive today through pilgrimages and commemorative monuments.

The specific feature of the Somme, as opposed to the Franco-German duel at Verdun the same year, is that it was the symbol of an international war. Three million soldiers confronted each other along a 40-km front. Allied plans for a massive attack in the Somme had been thwarted by the German offensive at Verdun which immobilized a large part of the French army. The British nonetheless continued to nurture the hope of a decisive breakthrough: this battle was to be the first large-scale engagement of what was known as ‘Kitchener’s Volunteer Army’.

After a week of non-stop bombardments, the Allied infantrymen ventured out of their trenches on 1 July 1916 to advance towards the German trenches in a landscape disfigured by 1,500,000 shells.But the German machine guns mowed down the attackers.
This was the bloodiest day in the entire history of the British army: 20,000 soldiers were killed and 40,000 others were wounded or missing. French successes in the south of the Somme could not be exploited.

In spite of the Allies’ repeated efforts and the use of new weapons such as the first tanks, the battle dragged on and finally got bogged down in the November mud which was so deep that the cannons could no longer be transported and men and horses alike were drowned in it.

For an Allied advance which did not go beyond 15 km, Great Britain had lost 400,000 men, Germany, 335,000, and France, 200,000. It was thus the deadliest battle of the war as well. And this is why the memory of the Somme remains alive for the British like that of Verdun for the FrencThe role of the Somme was not limited to 1916, however. In Spring 1918, a second Battle of the Somme took place after the rapid German offensive, which had reached the outskirts of Amiens. The war of movement began once again on the very sites which symbolized the horror of trench warfare and the industrial war.
But in August, the Allies launched the counter-offensive which marked the beginning of the end: “the black day of the German army” (in the words of General Ludendorff), 8 August 1918, definitively gave the initiative to the Allies with their success in the west of the Somme, at Villers-Bretonneux.