Under the command of Lieutenant General John Monash, the Australian Corps played a significant role in the Battle of Amiens, near Villers-Bretonneux. Secrecy shrouded this well-planned battle, which drew on the tactical successes at Hamel in July. At 4.20am on 8 August, the allies’ devastating artillery bombardment of German defence positions shattered the morning calm. Under cover of the creeping barrage, British, Canadian and Australian infantry advanced with support from tanks; in little more than three hours they overran German positions and achieved a decisive breakthrough. Allied forces captured more than 12 kilometres in the first day, as well as 29,144 German prisoners and around 350 guns, but they incurred many casualties. Among the key achievements on the “black day of the German army” was the Australian Corps’s capture of the “Amiens gun”, along with its locomotive, bogies and wagons.