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Battle of the Somme
July 1 – November 18, 1916· Battle· Europe
Well documentedSolid records, physical evidence or scientific consensus.
A British-French offensive on the Somme river in 1916 that gained about 10 km at a cost of over a million casualties.
See it on the Battles & Wars map →What happened
Planned to break the German line and relieve Verdun, it opened on July 1, 1916, after a week-long bombardment that failed to cut the barbed wire or destroy deep German dugouts. British infantry advancing in lines met machine-gun and artillery fire: 57,470 casualties, about 19,240 of them dead, the worst day in British military history. Fighting ground on until November 18, and tanks made their debut there in September. Estimates exceed one million casualties on all sides.
Why it matters
It became Britain's symbol of slaughter for little ground, yet it badly wore down the German army and taught the British army lessons it used to win in 1918.
How we know
Unit war diaries, casualty rolls, the Thiepval Memorial listing over 72,000 missing, and the 1916 documentary film The Battle of the Somme, seen by millions in Britain.
Still debated
Historians still argue whether commander Douglas Haig was a callous blunderer or a general learning a new kind of war, and whether German losses made it worthwhile.
Connections (5)
▸Machine gun (Maxim gun) caused mass casualties at Battle of the SommeWell documented
The connection
On July 1, 1916, the British bombardment failed to destroy German machine-gun crews sheltering in deep dugouts. They climbed out and fired into lines of British infantry crossing open ground. A few guns could sweep hundreds of meters of front, and many of the day's 57,470 British casualties fell in the first hour.
When and how
The Somme front in northern France, above all on the first day, July 1, 1916, as the British Fourth Army attacked German positions.
How we know
Battalion war diaries, survivors' accounts and German regimental histories describe machine guns cutting down the attacks; over the whole battle, artillery caused even more casualties.
Debates and open questions
How far British tactics, such as advancing at a walk with heavy packs, worsened the losses is debated; some units that rushed forward did better.
▸Battle of Verdun hastened the start of Battle of the SommeWell documented
The connection
The Allies had agreed in December 1915 on joint offensives for 1916, and Joffre and Haig chose the Somme. Verdun drained French divisions, so Britain took the main role, and France pressed for an earlier start, July 1 rather than August, to draw German forces away from Verdun. Germany did shift guns and men to the Somme, easing the pressure.
When and how
Agreed in principle at the Chantilly conference in December 1915; Joffre and Haig fixed on the Somme in early 1916; launched July 1, 1916, while Verdun was still raging.
How we know
Joffre's and Haig's letters and diaries record the French demand for an early start and the shrinking French share of the attack.
Debates and open questions
How much the Somme actually relieved Verdun is debated; Germany had already halted major attacks there by mid-July.
▸Battle of the Somme saw the first use of TankWell documented
The connection
Desperate for a breakthrough, Haig sent the first tanks into action at Flers-Courcelette on September 15, 1916, before they were fully ready. Of about 49 available, many broke down or got stuck, but some helped take the village of Flers. The debut gave away surprise but taught crucial lessons about using tanks.
When and how
Flers-Courcelette on the Somme front, September 15, 1916; British Mark I tanks with British, Canadian and New Zealand infantry.
How we know
Tank crew reports, war diaries and an airman's famous report that 'a tank is walking up the High Street of Flers' document the debut.
Debates and open questions
Whether using a few tanks early wasted the surprise of a later mass attack, as critics including Churchill argued, is still debated.
▸Barbed wire survived the barrage and stalled attackers at the Battle of the SommeWell documented
The connection
Britain's week-long bombardment before July 1, 1916, was meant to cut the German wire and smash the trenches. Many shells were shrapnel, which barely cut wire, and many failed to explode. Along much of the line, attackers found the wire intact, and on the first day Britain suffered about 57,000 casualties, including over 19,000 dead.
When and how
The Somme, northern France, June 24 – July 1, 1916; General Sir Douglas Haig and General Sir Henry Rawlinson's Fourth Army.
How we know
Battalion war diaries, the British official history, aerial photographs and German accounts describe uncut wire across many sectors.
Debates and open questions
Results varied by sector: in the south, beside the French, the wire was cut and attacks succeeded. Why planners spread the shells so thin is still argued.
▸Shell Crisis and Britain's Ministry of Munitions supplied the 1.5 million shells fired before the Battle of the SommeMostly agreed
The connection
By mid-1916 the ministry's new factories, plus orders from North America, had stockpiled shells for Britain's biggest bombardment yet: over 1.5 million fired in the week before July 1. But many were rushed out by inexperienced firms and workers, many were shrapnel, and a large share failed to explode, leaving German wire and dugouts intact.
When and how
British munitions factories and overseas contractors, 1915–16; the Somme front in northern France, June 24 – July 1, 1916.
How sure are we?
Ministry and army ordnance records, the British official history, and postwar studies of unexploded shells on the battlefield.
Debates and open questions
The dud rate is disputed, with estimates up to about a third. Historians debate whether poor quality or spreading the fire too thin did more harm.