The battle was preceded by artillery bombardment and the initial attack was on July 1, 1916. It ended approximately on November 18 of the same year when British Expeditionary Force commander Douglas Haig called off the battle.
On the first day of the battle, the British suffered casualties of 19,240 dead (the largest loss ever suffered by the British Army in a single day), 35,493 wounded, 2,152 missing and 585 taken prisoner for a total loss of 57,470. Initial casualties were especially heavy among officers, who still dressed differently from non-commissioned officers and other ranks, and whose uniforms the Germans had been trained to recognize. By the end of the battle, the British had suffered 420,000 casualties, the French lost 200,000 and the Germans 450,000 casualties.
The British used the tank for the first time in this battle with little effect, but the battle is best remembered as a prime example of the futile Allied tactic of frontal assault on defended positions that was the hallmark of fighting on the Western Front. However, during the subsequent months of fighting on the Somme, British Army tactics evolved from the grim lessons of the first few days to orchestrate effective combined operations between infantry, artillery and air force which were instrumental in eventually achieving total victory over the German Army on the Western Front in 1918. Without detracting from the carnage of the Somme and the futility of war, to this day, the British psyche is still deeply traumatised by the events of that first day on the Somme and fails to recognise the significance of what was actually achieved. The Battle of the Somme damaged the German Army beyond repair, after which it was never able to adequately replace its casualties with the same calibre of soldier that doggedly held its ground during most of the battle.
See also: History -- Military history -- List of battles -- World War I -- Somme -- Trench warfare