What was Britain's main reason for attacking at the somme?

Britain's main reason for attacking at the Somme in 1916 was to relieve pressure on French forces at Verdun and to break through German defenses along the Western Front. The offensive aimed to inflict significant casualties on the German army, thereby weakening its fighting capability. Additionally, it was intended to demonstrate the strength of the Allied forces and boost morale among troops and civilians alike. Ultimately, the battle became one of the bloodiest in history, highlighting the horrors of trench warfare.