The Battle of the Somme cost the British Army roughly 420,000 casualties, and this History Hit film sets out to explain why a battle meant to break the German line on the Western Front turned into one of the costliest disasters in British military history. Historians walk the ground in northern France, tracing the failed opening bombardment, the German dugouts that survived it intact, and the July 1st advance across open fields into machine-gun fire that produced roughly 57,000 British casualties on a single day. The film works through the tactical and command decisions behind the losses, from artillery shortfalls to the training and experience gap between the volunteer New Army battalions and the professional force Britain had lost earlier in the war. It also weighs the argument, made at the time and since, that the battle's grinding attrition eventually wore down German reserves enough to matter, against the scale of the losses it took to get there. Maps and archival photographs anchor the numbers to the terrain.