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.

The base of the German salient ran from Montdidier east and a little south, by way of Noyon, and linked up with the old line between St. Gobain and Anizy-le-Château, nine miles west of Laon, a distance of thirty-two miles in all. Just as the northern extremity of the German salient was flanked by the Arras ridges, so the southern extremity of thirty-two miles was flanked in the east by the watershed of the Oise and the Aisne, and eastward from the valley of the Oise, where it is joined by the ridge lying parallel to the Chiry-Lassigny highway.

The Allies holding the ridges north and south of the German salient were in a favorable position, and it seemed unlikely that the Germans would attempt to push farther westward without trying to capture the high approaches on their flanks.

It was known to the Allies through their aerial observers that the German armies, reenforced by new divisions that had been brought from Russia, were massing for another powerful attack.

On March 28, 1918, strong German forces drove back the British line south of the Somme to a line running west of Hamel, Marcelcave, and Demuin in the direction of Amiens. On the same date the Germans launched a terrific drive in the Scarpe sector with the purpose of capturing Arras and Vimy Ridge. Six German divisions were flung against the British positions, while four were held in reserve, but they failed to break through. To the south between Boiry and Serre eleven divisions attacked the British positions, but were forced back.

On the same date, in the Montdidier region, the French under Pétain not only held their ground but made gains. In the course of the evening and part of the night the Germans made violent attacks in the endeavor to eject the French from the villages of Courtemanche, Mesnil-St. Georges, and Assainvillers, which were won the day before, but in every instance were driven back with heavy losses. The French followed up their success by driving the enemy out of Monchel, which they occupied.

To the north of Montdidier Franco-British troops continued to hold the Germans on the Avre River and in front of Neuville, Mezières, Marcelcave, and Hamel.

It was evident that the great German offensive was losing force. The fighting was still intense at some points, but no operations were attempted on such a colossal scale as marked the fighting in the first week of the battle. At many places along the front of attack the Germans were being driven back and at others French and British were holding their positions firmly. Artillery battles had now taken the place of infantry fighting to a great extent, a sure sign that the German armies were in an exhausted condition and needed time to re-form and recuperate. As the Germans had been unable to drag much artillery with them during their advance the French had the advantage.

On March 28, 1918, the news that General Ferdinand Foch, chief of the French General Staff had been made generalissimo of all the Allied forces in the western theater of war was received with general satisfaction by the Allied nations. The Allies had long suffered from lack of coordination, while the Germans had not only profited by their own united direction, but were also advantaged by the frequently unrelated efforts of their enemies. General Foch, who was born in 1851, began mastering the strategy of war in 1870. He had studied German mentality. He counted on their repeating in future conflicts the maneuvers that had succeeded, and also expected them to make some of the old mistakes. Foch led the Ninth French Army at the Battle of the Marne, where, according to some military critics, he won first honors. In the spring of 1915 he led his army in the offensive between Armentières and Arras. After these operations he was surpassed in public opinion of the French army chiefs by Generals Pétain and Nivelle, whose wonderful leadership before Verdun made them famous throughout the world. When General Pétain succeeded Nivelle in May, 1917, as commander in chief in the field, General Foch took his place as chief of staff in Paris. President Wilson, who had been urging unify of command ever since the inter-Ally war conference at Paris in the winter of 1917, was among the first to congratulate General Foch on his appointment as generalissimo of all the Allied forces on the western front.