From La Maisonnette to Maucourt, they formed the sides of an enormous obtuse angle, the apex of which was Soyécourt.
The objective of the French 10th Army (General Micheler), disposed along the sides of this angle, was to widen the latter by means of continued thrusts in the direction of the southern end of the bend in the Somme. Its advance being then stayed by the important stronghold of Chaulnes, the latter was to be half-encircled, thereby seriously threatening the rear of the German positions south of the town.
The French offensive was launched on September 4. The outskirts of Deniécourt and Berny were reached in the first rush; in the centre, Soyécourt was carried; on the left, Vermandovillers was partly captured and Chilly passed by about half a mile.
On the 5th, the Germans counter-attacked unsuccessfully, and failed to stay the French advance. On the 6th, half the village of Berny was taken. In three days, 6,650 prisoners and 36 guns, including 28 heavies, were captured.
A fresh offensive was combined, with the attack of the 12th by the Franco-British troops north of the Somme, and that of the 15th by the British troops operating beyond Combles.
On the 17th, the conquest of Vermandovillers and Berny was completed, and on the 18th, the village of Deniécourt was encircled and captured.
On October 10th, the offensive was resumed after a heavy bombardment between Berny and Chaulnes. The hamlet of Bovent, north of Ablaincourt, was conquered, together with the western edge of Chaulnes Wood. Parts of these woods were captured in October, and at the beginning of November. The villages of Ablaincourt and Pressoire were also occupied.
Thanks to this slow but continuous advance, and to the capture of these various villages, the fortress of Chaulnes was outflanked and half-encircled.