In pictures: Battle of the Somme

Defences of the trenches at DompierrePA

The Battle of the Somme was one of the bloodiest of World War One, with more than one million people killed or wounded. It lasted five months as the British and French Armies fought the Germans on a 15-mile front.

British troops climbing from their trench on the first day of 'The Big Push' on the SommeGetty Images

British troops were sent into battle on 1 July 1916. It was the bloodiest day in the history of the British army, which suffered 57,470 casualties, including 19,240 deaths. The Somme offensive was intended to achieve a decisive breakthrough for the British and French allies after 18 months of trench warfare.

British infantrymen on the march towards the front lines in the River Somme valley.PA

General Sir Douglas Haig led the British troops, many of them volunteers, as they headed into battle on the Western Front.

A heavy shell exploding during the Battle of the SommeGetty Images

During the seven days leading up to the battle, the British army bombarded German lines with artillery. As 07:30 "zero hour" approached, a series of mines were detonated, including one at Hawthorn Ridge.

German troops outside their dug outs on the SommeGetty Images

But the German troops were largely unharmed in their protective dugouts. When the artillery bombardment ceased, the machine gunners came out and opened fire on the advancing troops with devastating results.

British infantrymen occupy a shallow trench in a ruined landscape before an advance during the Battle of the SommePA

Poor communications meant commanders knew little of what was happening on the battlefield. The 1st Newfoundland Regiment (not pictured) was almost wiped out as troops advanced towards no man's land and were shot dead before reaching their own front line.

Photograph of gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the SommeGetty Images

With no sign of the expected breakthrough, Gen Haig now regarded the Somme as an attritional or "wearing-out" battle. Machine guns inflicted heavy casualties on both sides.

An abandoned German 150 lb gun, after the Battle of the SommeGetty Images

The British scored one early strategic success. Fighting in the Somme led the Germans to call off their five-month offensive against the French at Verdun. Although fighting continued there until December it was the French who held the upper hand.

A German cannon buried under uprooted trees in Louage Wood during the offensive on the Somme, World War I, 10th October 1916Getty Images

The fighting dragged on with neither side making any real progress. The British Fourth Army is said to have advanced just 900m between 15 July and 14 September at the cost of 82,000 casualties.

Battle of Flers-CourceletteAlamy

The last Allied push began on 15 September, with the British engaged in the Battle of Flers-Courcelette, which also saw the tank make its debut. German defenders were forced to abandon their positions but there was still no breakthrough.

British soldiers negotiating a shell-cratered, Winter landscape along the River Somme in late 1916 after the close of the Allied offensivePA

Bad weather was turning much of the battlefield into a quagmire. The vermin-ridden trenches were havens for dirt and disease and battle was finally brought to a halt on 18 November.

Bapaume - Arras sector of the battlefield after the first Battle of the Somme had taken placeGetty Images

The British and French made only small advances against the Germans at a cost of more than a million casualties. Although many criticise Gen Haig's tactics, most historians agree the Somme drained the German Army and laid the foundations for an Allied victory in 1918.

All photographs courtesy Getty Images and Press Association

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