By January 1916 the war had become a stalemate. Millions had died and yet no side had achieved a decisive breakthrough. Austria-Hungary tripled the size of its armies to five million men. Germany doubled its forces to seven million. And in Britain men were volunteering to fight at the rate of up to 33,000 a day. 1916's Descent into Hell began at the French fortress city of Verdun. Entire villages were wiped off the map and both sides suffered over 300,000 casualties. At sea the British and German fleets fought the greatest naval battle in history, off the Jutland peninsula in the North Sea. Thousands died, but again no side achieved a crushing victory. And on the Western Front the newly recruited Pals battalions led the attack at 7.30am on 1st July 1916. A day that has gone down as the blackest day in the history of the British Army.