At on July 1916 the Battle of the Somme started with explosion of 17 massive 'mines' underneath enemy territory. Lochnagar was the largest of these. It remains "The largest crater ever made by man 'in anger'".
Photos show faces of First World War soldiers on the eve of battle
Knee-deep in mud: Wading through a trench on the Somme are Major Beauchamp Magrath (left) of the East Lancashire Regiment, killed on June and Captain Paul Hammond, right, who died on February The other two soldiers are not identified.
British soldiers eating hot rations in the Ancre Valley during the Battle of the Somme, October Colorized by Benjamin Thomas. a rare look at in color I hope future generations never forget their sacrifice
Soldiers of the Royal Irish Rifles waiting to join the offensive on the Somme on 1 July, There were British casualties that day - almost died. The battle continued until mid-November, but no other day produced such appalling losses.