Siegfried Sassoon, in reserve after going wire-cutting in No Man’s Land the night before, sat watching the battle unfold that first day on the Somme. “A small shiny black notebook contains,” he wrote a decade and a half later, “my pencilled particulars, and nothing will be gained by embroidering them with after-thoughts. I cannot turn my field-glasses onto the past”:

Our men in small parties (not extended in line) go steadily on to the German front-line. Brilliant sunshine and a haze of smoke drifting along the landscape. Some Yorkshires a little way below on the left, watching the show and cheering as if it were a football match. The noise almost as bad as ever. The sunlight flashes on bayonets as the tiny figures move quietly forward and disappear beyond mounds of trench debris…Shrapnel bursting in small bluish-white puffs with tiny flashes. The birds seem bewildered: a lark begins to go up and then flies feebly along, thinking better of it…I am staring at a sunlit picture of Hell, and still the breeze shakes the yellow weeds, and the poppies glow under Crawley Ridge where some shells fell a few minutes ago….

19,240 British soldiers were killed that day.