was to be masked by bombers flying up and down the German lines. The bombers were twin engine Handley Page O-400's whose engines were similar to the tanks. However the 2 RAF squadrons detailed to take part decided it was too hazardous to order planes into the air in the unseasonably dense fog, and asked for volunteers. Two volunteered from 207 Squadron, Captains Gordon Flavelle and William Peace, and both were awarded the Distinguished Flying Cross. Battle First phase The battle began in dense fog at 4:20 am on 8 August. Under Rawlinson's Fourth Army, the British III Corps attacked north of the Somme, the Australian Corps to the south of the river in the centre of Fourth Army's front, and the Canadian Corps to the south of the Australians. The French 1st Army under General Debeney opened its preliminary bombardment at the same time, and began its advance 45 minutes later, supported by a battalion of 72 Whippet tanks. Although German forces were on the alert, this was largely in anticipation of possible retaliation for their incursion on the sixth and not because they had learned of the preplanned Allied attack. Although the two forces were within of one another, gas bombardment was very low, as the bulk of the Allied presence was unknown to the Germans. The attack was so unexpected that German forces only began to return fire after five minutes, and even then at the positions where the Allied forces had assembled at the start of the battle and had long since left. In the first phase, seven divisions attacked: the British 18th (Eastern) and 58th (2/1st London), the Australian 2nd and 3rd, and the Canadian 1st, 2nd and 3rd Divisions. Troops of the 33rd Infantry Division of the U.S. Army National Guard supported the British attackers north of the Somme. The attackers captured the first German position, advancing about by about 7:30 am. In the centre, supporting units following the leading divisions attacked the second objective a further distant. Australian units reached their first objectives by 7:10 am, and by 8:20 am, the Australian 4th and 5th Divisions and the Canadian 4th Division passed through the initial breach in the German lines. The third phase of the attack was assigned to infantry-carrying Mark V* tanks; however, the infantry was able to carry out this final step unaided. The Allies penetrated well to the rear of