After an all-day battle north and south of the Somme, with Arras as the chief center, the British forces beat off the Germans, inflicting heavy losses. The attack on this new sector, delivered on a wide front north and south of the river Scarpe, was opened with an intense bombardment, and under cover of smoke clouds. The Germans were unable to break or even bend the British front and they lost a large number in killed and prisoners. South of the Somme, the British, subjected to fierce assaults, maintained their positions throughout the day, but the Germans brought forward fresh troops, and by sheer weight of numbers forced the British about nightfall to fall back on Chapilly. North of the Somme the British maintained their line intact. On the same day the French made substantial gains on the front from Lassigny to Noyon, advancing their line about ten kilometers (6.21 miles) to a depth of about a mile and a quarter. During the entire morning the Germans pressed vigorous assaults in the region of Montdidier in attempts to enlarge their gains west and south of the town. The French troops in spirited counterattacks drove the Germans out of the village of Courtemanche, Mesnil-St. Georges, and Assainvillers, and proceeded to occupy these places solidly. On the following day fresh German troops were thrown against the French Army maintaining the junction between the French and British lines. The French made a determined stand, but the German pressure forced them to retire toward the west. The Germans broke through at Montdidier and occupied that place. In order to keep in touch with the British the French were pushing northward to relieve part of the line of their ally which had been thrown back. At the same time the Germans made a demonstration at the point where the British and French lines joined. Employing large forces, they were able to make a breach in the British line, but the French sent forward cavalry and infantry into the gap and closed it. The salient which the Germans had now been pushing westward since the beginning of the offensive was now forty miles long at its farthest point, from Vimy Ridge, three miles south of Arras, to two miles south of Lassigny. Its greatest width was thirty miles, from the old line west of La Fère westward to Montdidier, the junction of the new western and southern fronts. On the north the territory was flanked by a semicircular ridge lying north and northeast of Arras, beginning with Notre-Dame-de-Lorette, six miles southwest of Lens, and ending at the much-fought-over Vimy Ridge.