British guns continued a massive week-long bombardment of German trenches along the Somme front, firing over 1.5 million shells in total by the time the attack began. Commanders believed the barrage would obliterate German wire and machine-gun nests, but poor shell quality and deep German bunkers meant defenses survived largely intact, setting the stage for catastrophic British losses on July 1.
For a solid week leading into July 1916, British artillery batteries along an 18-mile front unleashed one of the largest bombardments in history to that point, firing more than 1.5 million shells at German positions along the Somme river. General Douglas Haig and his staff believed, with almost theological confidence, that this weight of fire would flatten the German wire and pulverize the machine-gun emplacements, allowing British infantry to simply walk across No Man's Land afterward.
The reality was grimly different. A large fraction of the shells were duds or shrapnel rounds ill-suited to destroying deep fortifications, and German troops had constructed bunkers up to 30 feet underground, far below the bombardment's reach. They simply waited out the week of shelling and emerged largely unscathed once it lifted.
When the infantry finally advanced on July 1, they walked into machine-gun fire that had been expected to be silenced, resulting in roughly 57,000 British casualties on that single day, the bloodiest day in the history of the British Army. The preliminary bombardment of late June 1916 stands as a haunting lesson in the limits of firepower against fortified positions and the dangers of commanders' overconfidence in their own plans.