The attack was made by five divisions of the French Sixth Army either side of the Somme, eleven British divisions of the Fourth Army north of the Somme to Serre and two divisions of the Third Army opposite Gommecourt, against the German Second Army of General Fritz von Below. The German defence south of the Albert–Bapaume road mostly collapsed and the French had "complete success" on both banks of the Somme, as did the British from the army boundary at Maricourt to the Albert–Bapaume road. On the south bank the German defence was made incapable of resisting another attack and a substantial retreat began; on the north bank the abandonment of Fricourt was ordered. The defenders on the commanding ground north of the road inflicted a huge defeat on the British infantry, who had an unprecedented number of casualties. Several truces were negotiated, to recover wounded from no man's land north of the road.On this one day: "The Fourth Army took 57,470 casualties, of which 19,240 men were killed, the French Sixth Army had 1,590 casualties and the German 2nd Army had 10,000–12,000 losses."
July 1, 2016
"The first day on the Somme (1 July) saw a serious defeat for the German Second Army, which was forced out of its first position by the French Sixth Army...."