Watch World War I: The Great War Season 3 Episode 3 Online

In just one day almost 60,000 British soldiers were killed or wounded. Why was this first day on the Somme such a disaster for the British? World War I, trenches and barbed wire ran across the entire continent of Europe from the Mediterranean to the North Sea. At 7:30am on July 1st, 1916, after a devastating artillery bombardment lasting more than a week, 100,000 British soldiers waited in their trenches ready to advance on the German lines. They'd been told to expect minimal resistance, but as they picked their way slowly across no-man's-land, guns opened fire. Shells burst overhead, and waves of men were machine-gunned down. It was a military catastrophe of unprecedented proportions.