For many in Britain, the resulting battle remains the most painful and infamous episode of the First World War.
Pictures copyright Press Association

21. British infantrymen on the march towards the front lines in the River Somme valley.
British infantrymen on the march towards the front lines in the River Somme valley.:- Photo: PA

22. German prisoners help to carry British wounded back to their trenches after an attack by XIV (Irish) Corps on Bavarian units holding Ginchy during the Battle of the Somme.
German prisoners help to carry British wounded back to their trenches after an attack by XIV (Irish) Corps on Bavarian units holding Ginchy during the Battle of the Somme.:- Photo: PA

23. A British soldier gazes out of a dug-out, as the body of a dead German soldier lies nearby at Flers, during the battle of the Somme.
A British soldier gazes out of a dug-out, as the body of a dead German soldier lies nearby at Flers, during the battle of the Somme.:- Photo: PA

24. British infantrymen occupy a shallow trench in a ruined landscape before an advance during the Battle of the Somme.
British infantrymen occupy a shallow trench in a ruined landscape before an advance during the Battle of the Somme.:- Photo: PA
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